Supply Chain Management in Smart City Manufacturing Clusters: An Alternative Approach to Urban Freight Mobility with Electric Vehicles

Abstract

The development of green production types such as personalized production and shared manufacturing, which use additive technologies in city multifloor manufacturing clusters (CMFMCs), has led to an increase in last-mile parcel delivery (LMPD) activity. This study investigates the integration of electric vehicles and crowdshipping systems into smart CMMCs to improve urban logistics operations related to the distribution of products to consumers. The aim of this study is to improve the LMPD performance of these integrated systems and to provide alternative solutions for sustainable city logistics using the potential of crowdshipping and vehicle sharing fleets (VSFs) in the city logistics nodes (CLNs) of CMFMCs. The issues presented by the loading–unloading operations and sustainable crowdshipping scenarios for LMPD in CMFMCs are considered. This paper presents a new performance evaluation model for crowdshipping LMPD in CMFMCs using VSFs. The case study shows that the proposed model enables the analysis of LMPD performance in CMFMCs, taking into account their finite production capacity, and that it facilitates the planning of cargo turnover and the structure of VSFs consisting of e-bicycles, e-cars, and e-light commercial vehicles (e-LCVs). The model is verified based on a case study for sustainable LMPD scenarios using VSFs. The proposed model enables the planning of both short- and long-term logistics operations with the specified performance indicator of VSF usage in CMFMCs. The validity of using the integrated potential of crowdshipping and vehicle sharing services for LMPD under demand uncertainty in CMFMCs is discussed. This study should prove useful for decision-making and planning processes related to LMPD in CMFMCs and large cities.

1. Introduction

A city multifloor manufacturing cluster (CMFMC) is a group of production and residential multistory buildings with a city logistics node (CLN) in a territorially allocated part of the residential area of a large city in which the smart sustainable manufacturing of products and goods for the urban population and various enterprises and entities are performed [1,2]. Depending on the size of a large city, its infrastructure and its historically developed areas, several CMFMCs may be organized within it, differing in both size and possible production specializations [1,3]. Consumer demand for certain products and goods determines the organization in the CMFMCs of various forms of green production, such as mass production, mass-customized production, personalized production (including craft production), shared manufacturing and social manufacturing [3,4]. The main production units in CMFMCs are small and medium-sized enterprises, which implement types of production such as personalized production and shared manufacturing [4,5]. Competitive conditions in a CMFMC, determined by consumer demand, contribute to the use and renewal of green technologies (e.g., additive technology) and the implementation of sustainable business processes reengineering [6,7]. Grouping the same type of technological equipment in CMFMC buildings and the production network organization makes it possible to rationally distribute the energy and natural infrastructure resources of a large city, to reduce the intensity of loading–unloading and sorting operations, and to more fully utilize the potential of freight transport by reducing empty runs [4,8].

The material flow, i.e., the flow of components, products, and goods to manufacturers and customers, as well as the removal of production waste from CMFMC enterprises, is primarily carried out through the CLN, where the materials are sorted for delivery to the consumer [1,9]. The CLN of a CMFMC allows the division of material flows into intra-cluster and external ones, which helps to streamline the fleet of freight transport and its traffic in a large city [1,4]. The transportation of a set of IRTs in light e-trucks and CLN freight elevators is carried out as a city container representing multiple interconnected IRTs [1,10]. Information about the transported cargo and the location of IRTs in real time is provided to stakeholders using the Internet of Things (IoT) and blockchain technologies [11,12]. Such information contributes to the implementation of the closed-loop supply chain management concept in CMFMCs, aimed, in particular, at reducing downtime and empty runs of the IRTs [1,13]. The main tool for information support and digital services for actors of various business models within a CMFMC is the platform service supply chain of a focal firm [4,14].

This study focuses on logistics operations in CMFMCs related to the delivery of their non-perishable products to consumers through parcels [1,12]. The traditional last-mile parcel delivery (LMPD) scenario involves loading–unloading and sorting parcels in CLNs and then delivering them to consumers. However, the CLN and its personnel handle the entire volume of logistics operations with cargo, including parcels, from all CMFMCs and logistics facilities in a large city, and they also ensure the loading of parcels into PLCs [1]. The problem of implementing the traditional LMPD scenario is related to supply uncertainty, which is especially evident during the holidays and seasonal periods and leads to overloads and disruptions in the operation of the CLNs. This situation is common at CLNs due to the increase in the number of small parcels within the total volume of the finished products of CMFMC enterprises [4,15]. One of the possible solutions to the sorting operation problem in the CLNs of CMFMCs is to use the potential of vehicle sharing services for crowdshipping last-mile parcel delivery (LMPD) [16,17].

Information support and digital services for stakeholders in the planning and implementation of LMPD are provided by the integrated platform of crowdshipping and vehicle sharing services (PCVSS), which is one of the modules of the platform service supply chain [18,19]. The key means of LMPD implementation in a large city is a network of parcel lockers and luggage storage [20,21]. The parcel lockers are located near the places most visited by citizens in large cities and the places where consumers live and work, which makes it easier for them to receive parcels at a suitable time. The advantage of using parcel lockers in a large city for LMPD is the reliability and flexibility of logistics decisions made by all stakeholders on the PCVSS basis in real time (the possibility for the consumer to choose the appropriate parcel locker, the time of parcel receipt, etc.) [20,21]. Parcel and luggage storage lockers are actively used as the final point for the courier or crowdshipping deliveries of CMFMC products to consumers [20,22].

This study aims to improve LMPD performance in CMFMCs through the integrated use of the potential of crowdshipping and vehicle sharing services at CLNs. This involves analyzing issues related to the placement, size, and type of vehicle ratios of vehicle sharing fleets (VSFs) in order to identify sustainable crowdshipping scenarios and to evaluate performance for LMPD using e-bicycles, e-cars, and e-light commercial vehicles (e-LCVs) [15,19]. This study offers a new approach to the adoption of green freight logistics in CMFMCs and addresses gaps in urban freight transportation.

This paper is structured as follows: Section 2 reviews previous studies on crowdshipping for LMPD using vehicle sharing services; Section 3 details the materials and methods utilized in the study; Section 4 contains problem definition, notation, and assumptions; Section 5 presents the sustainable scenarios and performance evaluation model for crowdshipping LMPD in CMFMCs using VSFs; Section 6 discusses the results obtained and the available management solutions for implementing crowdshipping for LMPD in CMFMCs; finally, Section 7 outlines conclusions and future research directions.

2. Literature Review

2.1. Crowdshipping for LMPD in the CMFMCs

Solving the LMPD problem is one of the priorities of improving logistics processes in large cities [23,24]. The ever-growing demand for parcel delivery is associated with continuous changes in the structure of consumption and production in large cities, the growing share of personalized production and shared manufacturing, and the miniaturization and modularization of products and goods [25,26]. The situation with LMPD worsens during holiday periods, when the parcel flow significantly exceeds the freight transport capacity in the CMFMCs. The uneven parcel flow in clusters is also related to seasonal demand for certain goods. One of the most effective resources for improving the performance of LMPD is crowdshipping [18,27]. Buldeo Rai et al. [28] define crowdshipping as “an information connectivity enabled marketplace concept that matches supply and demand for any kind of transportation of goods with an undefined and external crowd that has free capacity with regards to time and/or space, participates on a voluntary basis, and is compensated accordingly”.

Crowdshipping LMPD uses a wide range of vehicles: bicycles, cars, LCVs, and various forms of urban public transport; the share of hybrid and electric vehicles in these groups is constantly growing [18,29]. The choice of a suitable vehicle and LMPD route by a crowdshipper is based on subjective assessments of personal capabilities and desires, which reflect various economic, social, and environmental conditions. The crowdshipper’s decision-making is based on analysis of delivery offers provided in real time by the PCVSS within CMFMCs and large cities [4,18]. The PCVSS provides actors with the opportunity to choose a suitable vehicle and to exchange parcels and information, and it enables financial transactions [18,19]. Crowdshipping LMPD supported by the PCVSS is carried out within the CMFMC by pedestrians, drivers, and passengers using e-bicycles, e-cars, e-LCVs, and urban public transport. Outside the CMFMC, but still within a large city, it is conducted using only e-cars and e-LCVs; urban public transport (e.g., taxis) are less common in this context [18,30]. The predominant use of pedestrians and cyclists for LMPD in CMFMCs helps to increase the share of green supplies [1,31]. Random couriers using the PCVSS compare tasks with other stakeholders, learn about the amount of remuneration for the service (the centralized model of the PCVSS generates pricing decisions itself), and plan the route and delivery time considering the requirements of the sender (recipient) [18,32].

The greatest difficulties in the organization and delivery of parcels in CMFMCs are associated with transportation between their CLNs, especially during holiday periods, which is due to the need to perform large volumes of loading–unloading and sorting operations. Therefore, the involvement of crowdshippers for LMPD both between the CLNs of CMFMCs and for the sorting and loading parcels into parcel lockers is a sustainable approach to the development of urban freight logistics, meeting the needs of citizens, manufacturers, logistics providers, and consumers within the framework of the smart city concept [1,18]. The involvement of crowdshippers in LMPD is regulated by the amount of remuneration for the service. It is evident that the amount of remuneration for parcel delivery increases with growth in personalized production and shared manufacturing during the holiday periods [4,18]. On the other hand, the implementation of peak LMPD requires the additional use of an e-LCV fleet, which may be idle with a decrease in production volume in CMFMCs. It is therefore necessary to also attract a carsharing fleet for crowdshipping LMPD [15]. In this case, the decrease in seasonal production volumes in CMFMCs does not have a significant impact on the downtime of the carsharing fleet. The disadvantage of using a carsharing fleet for last-mile inter-cluster parcel delivery is the limited cargo space of their e-cars compared to the capabilities of e-LCVs [29,33]; however, this disadvantage may be offset by the size of the carsharing fleet and the remuneration to crowdshippers for their logistics services.

Crowdshippers for LMPD in CMFMCs are drivers registered in the PCVSS, including the personnel of CLNs and adjacent service enterprises and shopping centers, as well as their clients, buyers, and visitors, and random drivers among vehicle renters [4,34]. Conventionally, all crowdshippers can be divided into two constantly changing groups: one that ensures LMPD within the boundaries of the CMFMC and another that operates beyond those borders. The first group of crowdshippers delivers parcels from a CLN to the declared parcel lockers of the same CMFMC; the second group delivers to CLNs and/or parcel lockers of other CMFMCs or districts in a large city [1,35].

The constant interaction of crowdshippers with the PCVSS via smartphones allows them to receive information about LMPD offers, the formation of random passenger groups, the departure and arrival times of the corresponding vehicle in real time, and the status of a scheduled crowdshipper, who receives an additional reward for their willingness to deliver parcels during certain periods [18,36]. Crowdshipper rewards are generated using centralized pricing based on transactions, membership fees, or their cross-subsidization [18,19]. The personnel of the CLNs and adjacent service enterprises and shopping centers, as well as some random drivers (among the group using cross-subsidies), all perform crowdshipping LMPD on their own initiative before/after their main work time for remuneration, mainly using e-LCVs. The remaining crowdshippers for LMPD in CMFMCs primarily use e-bicycles, e-cars, and e-LCVs. The development of the crowdshipping service for LMPD in CMFMCs and the increase in its efficiency is facilitated by competition between crowdshippers and corresponding digital platforms. The incentives for such competition are systems of rewards, training and e-learning for the implementation of smart sustainable deliveries, registrations and fines for various violations, the flexibility and speed of decision-making by the PCVSS, ease of customer service, and a wide range of services provided [18,37].

The practical implementation of crowdshipping LMPD in CMFMCs as an auxiliary model of cargo delivery by CLNs assumes the presence of an appropriate fleet of vehicles. Individual cars for LMPD are ineffective in terms of a sustainable approach to freight transportation, which aims to increase the share of vehicle sharing in an urban environment [38,39]. The throughput of CLNs with an existing fleet of light e-trucks designed for an average cargo turnover in clusters and under peak load conditions (e.g., during seasonal and holiday periods) is not able to cope with the resulting overloads [8,19]. In this regard, the organization of crowdshipping LMPD based on the vehicle sharing concept, with the involvement of crowdshippers for loading–unloading and sorting operations, seems to be the simplest solution for alleviating congestion in CLNs while simultaneously increasing their throughput.

2.2. Vehicle Sharing for the Implementation of Crowdshipping in City Multifloor Manufacturing Clusters

Modern society places high demands on the level of transport services in the context of a significant increase in travel needs in the urban environment, which is driven by the development of large cities and growing urban populations. Ensuring the mobility of citizens and the sustainability of the urban transport system based on a balance of economic, social, and environmental objectives is a priority direction for the development of large cities [40,41,42]. Heavy urban traffic with frequent traffic jams has a negative impact on both the mobility of citizens and urban sustainability. Increasing the sustainability of the urban transport system is associated with a reduction in the share of individual cars on urban roads due to the growth of e-mobility, vehicle sharing, and group trips [38,39]. The sharing economy, part of the concept of urban freight mobility as a service, is a socio-economic phenomenon in the era of Internet and the ubiquity of mobile devices. It suggests a shift away from vehicle ownership in favor of vehicle sharing based on a platform approach [4]. As a result, forms of vehicle sharing have emerged, including carsharing (paid, temporary, usually per-minute rental of a car) and carpooling (group trip on a private, rented, or business car) [43,44]. A sustainable approach to vehicle use involves organizing carpooling trips through a PCVSS within the vehicle sharing model. The PCVSS enables users to plan and agree on the terms of a shared trip, particularly when using a rented vehicle [42,45].

Vehicle sharing is one of the most popular and rapidly developing forms of sharing economy, becoming an alternative to using a personal car for city travel. It consists in the joint and organized use of a car without the need to own it. The selection and booking of the nearest car are carried out on the mobile application or website of the operator of the vehicle sharing company after the users completes the user registration procedure, which includes verifying the availability of their driver’s license, bank card, and other relevant information. The mobile application of the vehicle sharing company and smartphone allows the driver to check the technical condition of the vehicle and open/close the car doors, return it to the system, and to receive information about the distance travelled, trip time, and fees charged, which are automatically debited from their bank card. Drivers pay for the kilometers travelled in an urban environment and the time (in minutes) of booking/idle time of the car, depending on the time of day (night, morning, afternoon, or evening). Refueling, insurance, technical inspection and repair, and washing and parking in paid parking areas are all included in the cost of the vehicle sharing service [32,45]. Another advantage of vehicle sharing is the absence of a paid driver, which reduces the cost of using a rented car compared to the cost of a taxi [44]. Thus, sharing vehicles may provide greater comfort and flexibility than public transport and is cheaper than owning a private car. The vehicle sharing company provides stationary and non-stationary rental locations. In the first case, the customer picks up and returns the vehicle in stationary parking lots; in the second, they do so anywhere within the territorial range of the service [43,45].

Carsharing services in large cities are developing rapidly, and the vehicle rental fleet has grown significantly both globally and in Poland [46,47]. At the same time, there is a steady increase in European funding to support urban vehicle sharing projects and carsharing fleets of hybrid and e-cars as the basis for the sustainable development of smart cities [48,49]. The growth of vehicle sharing services in large cities, along with intense urban traffic and limited logistics capabilities for delivering cargo to consumers, has led to the use of rented e-bicycles, e-cars, and e-LCVs for crowdshipping LMPD [15,16]. Of course, the possibilities of delivering parcels using only rented cars are limited due to the limited size of their cargo spaces, even with the rear seats folded down, provided there are no passengers [32]; however, the possibility of using rented cars for LMPD helps reduce the intensity of loading–unloading and sorting operations in the CLNs. The consumer of vehicle sharing services is interested in participating in the LMPD, provided they receive a reward that compensates them for their personal time and expenses [16]. A preliminary analysis of the compatibility of the planned trip route with the proposed routes and parcel delivery time helps to reduce the loss of personal time and money to users of vehicle sharing services. Car sharing service users can choose to implement only the part of the proposed parcel delivery route that suits them. Vehicle sharing service users may opt to execute only a specific part of the proposed parcel delivery route. In this case, several drivers of rented vehicles take part in the delivery of the parcel to the customer within the framework of solving the many-to-one assignment [20,21]. Finding the optimal combination of the planned route of a rented vehicle and the LMPD presents a well-known and well-studied problem [16,50]. Along with routing issues, the quality of customer service is also considered based on a number of criteria, such as the timeliness of parcel delivery, the reputation of crowdshippers, and confidence in delivery completion [51].

The digital integration of crowdshipping and vehicle sharing services for the planning and implementation of LMPD in CMFMCs is carried out through the PCVSS platform. The PCVSS provides digital services to stakeholders (suppliers and consumers of parcels, crowdshippers as tenants of transport vehicles, managers of CLNs, and vehicle sharing companies), enabling them to mutually benefit from planning and executing sustainable LMPD within the CMFMCs of a large city [52,53].

This study focuses on the key aspects of the integrated use of crowdshipping and vehicle sharing services in CMFMCs to improve LMPD performance. These aspects relate to the placement of VSFs, their size and vehicle type ratios, the identification of sustainable crowdshipping scenarios, and performance evaluation for LMPD in CMFMCs using VSFs.

3. Materials and Methods

Figure 1 shows the CMFMCs within the structure of residential areas (RAs) in a large city. The products from these CMFMCs are intended for the urban population and various enterprises and organizations in the city. The practically relevant context is based on examples of largest number cities in Poland, such as, Warszawa, Poznan, Wroclaw, Katowice Lodz and Szczecin.

In the course of their production activities, the enterprises of the CMFMCs collaborate with each other as well as with suppliers and consumers. Notable participants in this network include the following: CLNs; energy parks (where electricity generation is provided by renewable sources); advanced technology and educational parks (ATEPs) (universities, research institutes, medical centers, etc.); industrial and technology parks (ITPs); recycling, treatment, and energy parks (RTEPs); and port and logistics facilities [1,11]. Electricity generation in RTEPs is provided by non-renewable sources. All of the listed parks and large economic entities have their own logistics facilities (e.g., each ATEP has its own city logistics center (CLC)), in which cargo is stored and processed for further shipment to consumers [1]. LMPD in a large city is mainly carried out using parcel lockers that are installed within the territories of CMFMCs, including their CLN, and outside them [17,20]. The parcel lockers in the residential part of a large city (including ATEP) serve the city population in their areas of residence, work, education, and treatment and are loaded with parcels coming from the CLNs of the CMFMCs.

In this paper, the CMFMCs are assigned numbers (e.g., the first CMFMC is referred to as CMFMC-1), and transport lines are assigned a set of CMFMC numbers through which they pass (e.g., in Figure 1, the CMFMCs numbered 1, 2, 3, 4 are connected by transport line 1–2–3–4).

Figure 2 shows the structure of the LMPD in the CMFMCs, where personalized production and shared manufacturing are the dominant types of production organization [4].

Finished products at the CMFMS enterprises are packaged in the form of parcels with a QR code that contains information about the cargo being transported, indicating the final delivery point and allowing stakeholders to track the delivery of parcels in real time. Parcels are sorted by the final delivery point using a QR code and packed into delivery bags (plastic boxes). The delivery bags are placed in the IRT, and information about the transported products is automatically entered into its reader device using IoT-Blockchain technologies. The average capacity of the IRT is four delivery bags with parcels. The loaded IRT enters the transfer area of the ground floor by means of the freight elevator of the production building, where, together with other IRTs, the city container (CC) is formed. The CC usually consists of six IRTs with compatible freights, which, after loading into a light e-truck, is delivered to the CLN of the CMFMC [1,4]. In the CLN, the new CCs are formed from the received IRTs according to their final CLN delivery and then transported there via light e-trucks. The IRTs also deliver parcels and bags to the parcel lockers and luggage storage facilities at the CLN parking area. The parcel lockers and luggage storage facilities at the CLN parking area are located in the adjacent area (within 10 m) and are divided into three groups. The first group is represented by the parcel lockers at the CLN parking area (PLPs) for final points of LMPD; the second and third group are represented by the luggage storage facilities for the final (LSFTs) and intermediate (LSITs) trans-shipment points of delivery bags. From the LSFTs, delivery bags are transported by crowdshippers to the PLCs within the same CMFMC, while, from the LSITs, bags are delivered to the PLPs, LSFTs, and LSITs of other CLNs in the CMFMCs.

The final points of crowdshipping LMPD are PLPs or PLCs (less often, an enterprise or organization), agreed upon by the consumer with the manufacturer at the stage of issuing a smart contract for the product manufacture. The first intermediate point of parcel delivery is the CLN of the GMFMC, in which it was prepared by the manufacturer. The last intermediate point of parcel delivery is a CLN or other logistics facility in a large city, from which it is the shortest route to the final delivery points (PLPs or PLCs).

In most cases, the first and last intermediate parcel delivery points are the same. In this case, registered crowdshippers among the first conditional group choose parcels for delivery to the PLPs and/or PLCs via the PCVSS, taking into account the planned and recommended delivery route, the cargo space and trip time of the rented vehicle, and the remuneration received. The next stage is the delivery of parcels to the PLCs by means of rented vehicles. The average cargo space of a two-wheeled bicycle is one delivery bag with parcels or 0.25 IRT. The capacities of individual brands of electric vehicles of the VSF used in Poland and their technical characteristics are presented in

Table 1. Technical characteristics of VSFs at the CLN parking area.

Vehicle Model	Fleet Type	Engine Type	Number of Seats	Cargo Space, m3	Average Transportation Carrying Capacity, IRT
Renault Kangoo Van E-Tech	LCV, Small Van	Electric	2	3.3	2.0
Renault Kangoo Z.E.	LCV, Small Van	Electric	2	4.2 (4.0–4.6)	2.5
Nissan Townstar Van	LCV, Small Van	Electric	2	3.3	2.0
Nissan e-NV200	LCV, Van	Electric	2	4.2	2.5
Škoda Enyaq	Car	Electric	5	0.585	0.5
Volkswagen ID.4	Car	Electric	5	0.543	0.5

[29,32,54].

In the case of using several intermediate parcel delivery points in the form of CLNs, crowdshippers from the second conditional group similarly select delivery bags with parcels for their transportation via e-cars or e-LCVs to a suitable intermediate or final point (CLN) delivery destination (see Figure 2). The transportation of goods to an intermediate or final point (CLN) destination is carried out via the recommended transport lines shown in Figure 1. The subsequent delivery of parcels to the PLCs located at the CMFMC of the final CLN (point) delivery is carried out by crowdshippers from the first conditional group, similar to the scheme shown in Figure 1 and as described earlier. The return of parcels to manufacturers by customers is facilitated through the PLPs via the delivery and return services of the CLNs. In the event of late parcel receipt from the PLCs, their return to the CLN for short-term storage or to the manufacturer is carried out by public logistics companies that provide a courier, package delivery, and express mail service.

Figure 3 shows a ground floor plan of the multi-story parking area of the CLN with surrounding area to accommodate the VSFs. The possibility of stationary parking for LMPD fleets increases the sustainability, safety, and performance of urban freight transportation within the framework of the urban consolidation center concept [18,55].

The VSFs at the CLN parking area are located on the ground floor. The parking garage provides parking spaces only for fleets of rental e-cars, e-LCVs (directly on the parking area), e-bikes, and e-scooters (on the area adjacent to the parking lot). The CLN parking area is adjacent to the shopping center, and its upper floors (free from the VSFs) also serve the vehicles of their visitors (in some cases, crowdshippers with rental vehicles). The VSFs at the CLN parking area serve customers and crowdshippers registered on the PCVSS.

On the territory adjacent to the CLN parking area for the VSFs, there are PLPs, LSFTs, and LSITs, into which parcels (PLPs) and bags with parcels (LSFTs and LSITs) are loaded by the CLN’s delivery and return service and by crowdshippers. The PLPs are designed for receiving and loading parcels by consumers (in case of product complaints for subsequent delivery of the parcels to the manufacturer). The LSFTs and LSITs are the final and intermediate points of crowdshipping delivery and receipt of parcels and delivery bags. The placement of the PLPs, LSFTs, and LSITs near the CLN parking area (within 10 m) and shopping center makes them the preferred final and intermediate CLNs for last-mile parcel delivery [20,21].

The delivery (receiving) of parcels and bags to the PLPs, LSFTs, and LSITs by the CLN’s delivery and return service is carried out using IRTs. The transportation of parcels and delivery bags by customers and crowdshippers between PLPs, LSFTs, LSITs, and rental vehicles is carried out using carts located in designated CLN parking areas. An essential element of the CLN parking area is the availability of charging stations for refueling the VSFs, which are located outside the parking spaces and use renewable energy sources [56].

The development of a performance evaluation model of crowdshipping for LMPD in CMFMCs using fleets is based on the fundamental principle of MFA (material flow analysis), which is used to study the material and product flow within manufacturing ecosystems and involves ensuring a balance between finite production capacities in each CMFMC of a large city and freight transport delivery capabilities [57,58]. The study of sustainable scenarios for LMPD was conducted under the conditions of the finite production capacity of CMFMC buildings that use additive technologies and the principles of floor-by-floor grouping of technological equipment. Numerical calculations of the finite production capacity of CMFMC buildings in this case study were carried out according to Deja et al. [4].

4. Problem Definition, Notation, and Assumptions

4.1. Problem Definition

The CMFMC product flow in the form of parcels in IRTs passes through its CLN, dividing cargo flows into intra- and inter-clusters. Cargo in the IRTs is presented either in parcels or in delivery bags with parcels, and requires extensive sorting into delivery directions both within the CMFMC and outside it. Scenarios for parcel delivery in IRTs after sorting include loading into light e-trucks and courier delivery to the PLCs (less often, directly to consumers) or delivery to other CLNs of CMFMCs in the form of CCs. After CCs with parcels arrive at other CLNS, the scenarios of intra-cluster courier distribution of parcels to PLCs are repeated. Evidently, such scenarios for LMPD under the uncertainty of their generation in CMFMCs are not always acceptable and may lead to CLNs becoming overloaded. The uneven workload of CLNs at different times of the year requires a temporary increase in personnel and the allocation of additional space for organizing loading–unloading and sorting operations. In this regard, it is appropriate to consider sustainable scenarios for LMPD using crowdshippers and VSFs, as well as to evaluate delivery performance. This should account for the finite production capacity of parcel generation in CMFMCs during different periods of the year and for the composition and size of the VSFs, all of which will make this logistics process more sustainable and smart.

Figure 4 illustrates the application of the material balance principle for the LMPD within the CMFMCs of a large city.

4.2. Notation

Sets:		unit
$F$	set of production buildings in a CMFMC, indexed by f ∈ F;
$K$	set of CMFMCs in a large city, indexed by k ∈ K;
$I$	set of e-bicycles in VSFs of a CMFMC, indexed by i ∈ I;
$J$	set of e-cars in VSFs of a CMFMC, indexed by j ∈ J;
$Q$	set of e-LCVs in VSFs of a CMFMC, indexed by q ∈ Q;
$D$	day.
Parameters:
Independent parameters
$H_f$	number of floors of CMFMC buildings	unit
${\epsilon }_f$	number of freight elevators of CMFMC buildings	unit
${\lambda }_f$	number of IRTs in the freight elevator of CMFMC buildings	unit
$m_f$	coefficient of capacity freight elevator losses of CMFMC buildings	%
$T_f$	freight elevator round trip time of CMFMC buildings	hours
$E_C$	throughput of freight elevators of CMFMC buildings	IRTs/h
$w_P$	share of parcels in total production volume in CMFMC buildings	%
$N_C$	finite production capacity of parcel generation in CMFMC buildings	IRTs/h
$N_{C.k}$	finite production capacity of parcel generation in CMFMC buildings	IRTs/h
$N_U$	finite production capacity of parcel generation in CMFMCs	IRTs/h
$G_C$	LMPD performance in CMFMC	IRTs/h
$G_U$	LMPD performance in CMFMCs	IRTs/h
$w_C$	share of parcels in total production volume delivered in a CMFMC	%
$z_C$	share of parcels in total production volume in a CMFMC coming from outside	%
$w_{C.k}$	share of parcels in total production volume delivered in a CMFMC	%
$z_{C.k}$	share of parcels in total production volume in a CMFMC coming from outside	%
$B_C$	e-bicycle throughput of VSFs at the CLN parking area of a CMFMC	IRTs/h
$C_C$	e-car throughput of VSFs at the CLN parking area of a CMFMC	IRTs/h
$L_C$	e-LCV throughput of VSFs at the CLN parking area of a CMFMC	IRTs/h
$B_{C.k}$	e-bicycle throughput of VSFs at the CLN parking area of a CMFMC	IRTs/h
$C_{C.k}$	e-car throughput of VSFs at the CLN parking area of a CMFMC	IRTs/h
$L_{C.k}$	e-LCVs throughput of VSFs at the CLN parking area of a CMFMC	IRTs/h
$a_i$	average share of e-bicycles from VSFs involved in crowdshipping LMPD	%
$a_j$	average share of e-cars from VSFs involved in crowdshipping LMPD	%
$a_q$	average share of e-LCVs from VSFs involved in crowdshipping LMPD	%
$b_i$	number of e-bicycles in VSFs of a CMFMC	unit
$c_j$	number of e-cars in VSFs of a CMFMC	unit
$l_q$	number of e-LCVs in VSFs of a CMFMC	unit
$b_C$	total number of e-bicycles in VSFs in CMFMCs	unit
$c_C$	total number of e-cars in VSFs in a CMFMC	unit
$l_C$	total number of e-LCVs in VSFs in a CMFMC	unit
$S_i$	average transportation carrying capacity of an e-bicycle	IRT
$S_j$	average transportation carrying capacity of an e-car	IRT
$S_q$	average transportation carrying capacity of an e-LCV	IRT
${\tau }_i$	average trip time of an e-bicycle	hours
${\tau }_j$	average trip time of an e-car	hours
${\tau }_q$	average trip time of an e-LCV	hours
${\tau }_{D.i}$	average downtime of an e-bicycle	hours
${\tau }_{D.j}$	average downtime of an e-car	hours
${\tau }_{D.q}$	average downtime of an e-LCV	hours
$r_C$	ratio of working hours of CMFMC personnel and crowdshippers
Dependent parameters
$P_C$	crowdshipping LMPD performance ratio in CMFMC buildings
$P_{C.d}$	daily crowdshipping LMPD performance ratio in CMFMC buildings
$P_U$	crowdshipping LMPD performance ratio in all CMFMCs
$P_{U.d}$	daily crowdshipping LMPD performance ratio in all CMFMCs
$P_{CB}$	crowdshipping LMPD performance ratio for e-bicycles in CMFMC buildings
$P_{CC}$	crowdshipping LMPD performance ratio for e-cars in CMFMC buildings
$P_{CL}$	crowdshipping LMPD performance ratio for e-LCVs in CMFMC buildings
$P_{UB}$	crowdshipping LMPD performance ratio by e-bicycles in all CMFMCs
$P_{UC}$	crowdshipping LMPD performance ratio by e-cars in all CMFMCs
$P_{UL}$	crowdshipping LMPD performance ratio by e-LCVs in all CMFMCs
$V_{CV.d}$	daily volume of parcels passing through VSFs of a CMFMC	IRT
$V_{UV.d}$	daily volume of parcels passing through VSFs of all CMFMCs	IRT
$V_{C.d}$	daily volume of parcels passing through CLN of a CMFMC	IRT
$V_{U.d}$	daily volume of parcels passing through all CLNs of CMFMCs	IRT
$D_{C.i.d}$	daily usage rate of VSF of e-bicycles i for crowdshipping LMPD in CMFMC
$D_{C.j.d}$	daily usage rate of VSF of e-cars j for crowdshipping LMPD in CMFMC
$D_{C.q.d}$	daily usage rate of VSF of e-LCVs q for crowdshipping LMPD in CMFMC
$D_{U.i.d}$	daily usage rate of VSF of e-bicycles i for crowdshipping LMPD in CMFMCs
$D_{U.j.d}$	daily usage rate of VSF of e-cars j for crowdshipping LMPD in CMFMCs
$D_{U.q.d}$	daily usage rate of VSF of e-LCVs q for crowdshipping LMPD in CMFMCs

4.3. Assumptions

The following observations and assumptions are considered in the proposed model:

• The main limitation of the finite production capacity of a CMFMC is the freight elevators throughput of their production buildings. The finite production capacity of parcels generation in each CMFMC is defined taking into account the throughput capacity of freight elevators in its production buildings using the following equations [4,58]:

$$E_C=\sum _{f\in F}0.01{m_f\epsilon }_f{\lambda }_f{H}_f/T_f,$$

(1)

$$N_C=w_P{E}_C,$$

(2)

and, from the finite production capacity of parcel generation in all CMFMCs [4], we calculate

$$N_U=E_U=\sum _{k\in K}{N}_{C.k}.$$

(3)

2.

Each trip of a rented vehicle of any CLN parking area VSF includes the delivery of parcels corresponding to the volume of its average transportation carrying capacity (Table 1).

3.

The trip time of a rented vehicle from a VSF is the time the vehicle is absent from any CLN parking area.

4.

The percentage of vehicle types in the VSF range is the same in each CMFMC.

5.

The size of the VSFs at the CLNs of each CMFMC corresponds to its finite production capacity of parcel generation.

5. The Alternative Approach to Urban Freight Mobility in CMFMCs

5.1. Sustainable Crowdshipping Scenarios for LMPD in CMFMCs Using VSFs

Figure 5 illustrates the sustainable crowdshipping scenarios for LMPD using VCFs in CMFMCs. The letter designations in Figure 5 correspond to the designations of logistics operations in Figure 2.

Scenarios 1 and 2 are used for LMPD within each CMFMC; scenario 3 is used for inter-cluster deliveries. In all scenarios, the final destination of the LMPD is the PLPs or PLCs located within the boundaries of CMFMCs and adjacent territories. Each of the proposed scenarios is planned by production enterprises at the stage of receiving an order for the manufacture of products, agreeing with the customer on the time and point (parcel locker) of parcel delivery, and taking into account the data from the daily profiles of the parcel delivery performances of the current and previous years in the CMFMC. The intensity of parcel generation in a CMFMC depends on the consumer demand and production capacity of enterprises as well as the additive technologies and equipment used. Taking into account the uncertainty of supplies and current changes in the parcel generation intensity in CMFMCs, the final choice of scenario for timely delivery to the parcel locker is accepted by the manufacturer and adjusted during its implementation in real time.

Scenario 1. Consumers of parcels, after receiving the notification on their smartphone that their package has been placed at the PLPs of the CLN parking area, may receive it by walking to the location or arriving via public transport, their own vehicle, or a rented vehicle. The vehicle may be parked at the parking lot of a shopping center (upper floors of the CLN parking garage) or at the CLN parking area, provided that it belongs to the VSFs. After receiving the parcel, the consumer may choose the appropriate option for its delivery to the destination from among the previously listed ones. If it is necessary to return the parcel, the recipient may also send it to the manufacturer within the prescribed period using the PLPs.

Scenario 2. The simplest scenario involves the consumer receiving the parcel at the PLPs and delivering it directly to their home; however, the consumer may take advantage of the location of the CLN parking area to initiate a new parcel delivery. For example, having arrived for a parcel on their own bicycle and receiving it, the consumer may turn into a crowdshipper (register on the PCVSS), who then rents a vehicle, selects an appropriate delivery route, receives delivery bags with parcels from LSFTs, delivers them to PLCs, and receives remuneration for the rendered logistics services to their bank account. The consumer can also, while performing the tasks of a crowdshipper, use the rented car to run personal errands (e.g., shopping, visiting a doctor, picking up a child from school and taking them home). After returning to the CLN parking area, the consumer–crowdshipper returns the e-car to the renter and returns home on their bicycle.

It is important to note that delivery bags with parcels received from ISFTs at the CLN parking area are intended only for delivery to the corresponding PLCs of their CMFMC. The crowdshipper may familiarize themselves with the recommended delivery routes for delivery bags with parcels before receiving them on the PCVSS, compare them with their planned route, and select the appropriate trip option. The crowdshipper’s remuneration for the logistics service performed is determined only by the cost of delivery along the recommended route. The crowdshipper loads each parcel from delivery bags into the appropriate PLCs. If it is necessary to return the parcel, the recipient may send it to the manufacturer within a specified period, also using PLPs or PLCs.

Scenario 3. Registered crowdshippers receive delivery bags with parcels from LSITs at the CLN parking area, which are intended for delivery to the LSITs, PLPs, and LSFTs of another CLN parking area within the CMFMCs. In this scenario, inter-cluster last-mile parcel deliveries are implemented. The inter-cluster LMPD is carried out one-way, two-way, or quasi-two-way. In the first case, the crowdshipper, after planned trips and the delivery of parcels to another CLN parking area, parks there and returns the vehicle to the renter. In the second and third cases, the crowdshipper returns in the original vehicle (two-way inter-cluster parcel delivery) or in a rented vehicle (quasi-two-way inter-cluster parcel delivery) to the original CLN parking area and returns the vehicle to the renter. In any case, the rented vehicle starts the trip from the CLN parking area of the corresponding CMFMC and therefore has the opportunity to participate in the LMPD. The crowdshipper’s interest in receiving a reward for the timely delivery of parcels helps to reduce empty runs (without parcels) of rented vehicles. Within a large city, in most cases, quasi-two-way or two-way inter-cluster transportation is carried out. Quasi-two-way inter-cluster transportation is typical for trips to work, exhibitions, and shopping centers, etc. Two-way inter-cluster transportation is typical for business trips, doctor visits, and trips with children, etc.

The implementation of inter-cluster transportation by crowdshippers is associated with the selection of suitable conditions for parcel delivery in the PCVSS platform. The criteria for such a choice are the recommended delivery route and the planned travel time in real time, remuneration for the service considering the number of transported delivery bags with parcels, the free cargo space in the rented vehicle as well as the costs for its rental and charging, and additional time spent. If the trip conditions are suitable according to the main criteria, the crowdshipper may agree to implement the inter-cluster delivery of parcels. The crowdshipper’s decision to implement inter-cluster transportation is also based on their previous experience of such trips.

As an example, consider a situation in which a crowdshipper, having selected the CLN parking area of the CMFMC-k for LMPD, arrives in a rented e-LCV with three bags of parcels. They load the parcels from one bag into the PLP, and the other bag into the LSFT, and the third into the LSIT. In this case, parcels from the PLP parcel terminal will be received by their customers (scenario 1). From the LSFT, another crowdshipper will receive a delivery bag and accordingly load the parcels into the PLCs of CMFMC-k (scenario 2). Finally, from the LSIT, the third crowdshipper will receive a delivery bag and bring it to another CLN parking area in CMFMC-2 (scenario 3). The third crowdshipper may also take two more delivery bags to repeat the scenario of the LMPD of the first crowdshipper. These considered example demonstrates a wide variety of mixed scenarios for inter-cluster parcel delivery in a large city. Selecting the most sustainable crowdshipping scenarios among them for LMPD in CMFMCs using VSFs is a priority approach in decision-making.

Sustainable crowdshipping scenarios for LMPD in CMFMCs using VSFs are aimed at ensuring the quality of logistics services based on IoT-Blockchain technologies and are associated with the reduced consumption of natural resources (primarily electricity) through the implementation of reverse supply chains and closed-loop supply chain management, which reduces empty runs (without parcels), selects the right vehicles and best routes thanks to urban traffic monitoring, communicates between crowdshippers, and provides real-time information support from the PCVSS [19,59]. A significant aspect of the implementation of sustainable scenarios for LMPD in CMFMCs is the interest of crowdshippers in such supply chains using VSFs as a potentially low-cost and environmentally friendly alternative to vehicle ownership [60,61].

A simplified approach to the selection of sustainable scenarios prioritizes the use of the following vehicles: (i) e-bicycles in the implementation of scenario 2, as they are the most environmentally friendly vehicles; and (ii) e-LCVs for scenario 3, since they offer more cargo space than e-cars, all other factors being equal. However, under conditions of demand uncertainty, the decision-making process for selecting sustainable scenarios based on integrated VSFs relies on performance evaluation for crowdshipping LMPD in CMFMCs, taking into account their final production capacity. This assessment is also used in planning cargo turnover and VSF structure. The following subsection presents a performance evaluation model for crowdshipping LMPD in CMFMCs using VSFs.

5.2. A Performance Evaluation Model for Crowdshipping LMPD in CMFMCs Using VSFs

The structure and size of the VSFs should simultaneously meet the needs of the population and parcel manufacturers of the CMFMC for the services of vehicle sharing and crowdshipping LMPD, as well as meeting the economic, social, and environmental needs of stakeholders. Consensus among all stakeholders in the organization of crowdsourcing LMPD is the main condition for the successful functioning of the VSFs in CMFMCs. Advertising, education, and the training of the population to use vehicle sharing services and crowdsourcing activities in CMFMCs also play a significant role in this issue. It is evident that the structure and size of the VSFs may exceed the needs for crowdshipping LMPD during periods of high demand for vehicle sharing services.

The planning of the structure and size of the VSFs at the CLN parking area is based on ensuring a balance between the finite production capacity of parcel generation in the CMFMC and its throughput for crowdshipping LMPD. Long-term planning of the structure and size of the VSFs should also take into account the dynamics of population growth and consumption and increasing production capacity in CMFMCs.

The LMPD performance in a CMFMC and in all CMFMCs is as follows:

$$G_C=0.01\left(w_C+z_C\right)N_C;$$

(4)

$$G_U={0.01N}_U\sum _{k\in K}\left(w_{C.k}+z_{C.k}\right).$$

(5)

The VSF throughput at the CLN parking area for e-bicycles, e-cars, and LCVs is as follows:

$$B_C=0.01\sum _{i\in I}{a}_i{S}_i{b}_i/\left({\tau }_i+{\tau }_{D.i}\right) ;$$

(6)

$$C_C=0.01\sum _{J\in J}{{a_{j}S}_{j}c}_j/\left({\tau }_j+{\tau }_{D.j}\right);$$

(7)

$$L_C=0.01\sum _{q\in Q}{a}_q{S_{q}l}_q/\left({\tau }_q+{\tau }_{D.q}\right).$$

(8)

The implementation of crowdshipping LMPD in each CMFMC is based on the balance between its LMPD performance and the transport capabilities of VSFs at the CLN parking area [2]:

$$r_C{G}_C=B_C+C_C+L_C.$$

(9)

This balance should be observed in each CMFMC; as a result, in a large city, we calculate

$${r_{C}G}_U=\sum _{k\in K}\left(B_{C.k}+C_{C.k}+L_{C.k}\right).$$

(10)

The performance evaluations for crowdshipping LMPD using VSFs in a CMFMC and in all CMFMCs of a large city are based on the use of crowdshipping LMPD performance ratios:

$$P_C={\displaystyle \frac{B_C+C_C+L_C }{r_C{G}_C}};$$

(11)

$$P_U=\sum _{k\in K}{\displaystyle \frac{B_{C.k}+C_{C.k}+L_{C.k}}{r_{C.k}{G}_{C.k}}};$$

(12)

$$0\le P_C\le 1; 0\le P_U\le 1.$$

(13)

The evaluations of the contribution of each type of vehicle from the VSFs to the performance of crowdshipping LMPD in a CMFMC and in all CMFMCs of a large city are based on the use of the following indicators:

$$P_{CB}={\displaystyle \frac{B_C}{r_C{G}_C}} ; P_{CC}={\displaystyle \frac{C_C}{r_C{G}_C}} ; P_{CL}={\displaystyle \frac{L_C}{r_C{G}_C}},$$

(14)

$$P_{UB}=\sum _{k\in K}{\displaystyle \frac{B_{C.k}}{r_{C.k}{G}_{C.k}}}; P_{UC}=\sum _{k\in K}{\displaystyle \frac{C_{C.k}}{r_{C.k}{G}_{C.k}}}; P_{UL}=\sum _{k\in K}{\displaystyle \frac{L_{C.k}}{r_{C.k}{G}_{C.k}}};$$

(15)

$$P_C=P_{CB}+P_{CC}+P_{CL};$$

(16)

$$P_U=P_{UB}+P_{UC}+P_{UL};$$

(17)

$$0\le P_{CB}\le 1; 0\le P_{CC}\le 1;0\le P_{CL}\le 1;0\le P_{UB}\le 1; 0\le P_{UC}\le 1;0\le P_{UL}\le 1.$$

(18)

The indicators $P_C, P_U, P_{CB}, P_{CC},P_{CL},P_{UB}, P_{UC}, \mathrm{and} P_{UL}$ characterize the current VSF’s needs and its use for crowdsourcing LMPD in the CMFMCs.

The task of determining the optimal size, structure, and distribution of VSFs in CMFMCs is based on the use of the simplex method by searching the maximum of the objective function, calculated based on Equations (6)–(8) and (10) [62]:

$$\Omega =\sum _{k\in K}(B_{C.k}+C_{C.k}+L_{C.k})\to max,$$

(19)

under the following limitations:

$$\sum _{k\in K}(B_{C.k}+C_{C.k}+L_{C.k})\le {r_{C}G}_U:$$

(20)

$$\sum _{k\in K}\sum _{i\in I}{b}_i \le b_C:\sum _{k\in K}\sum _{j\in J}{c}_j \le c_C:\sum _{k\in K}\sum _{q\in Q}{l}_q \le l_C.$$

(21)

The groups of daily indicators for the formal description and forecasting of VSF usage for crowdshipping LMPD in CMFMCs based on daily freight mobility statistics are calculated using the following equations:

$$P_{C.d}={\displaystyle \frac{V_{CV,d}}{V_{C.d}}}; P_{U.d}={\displaystyle \frac{V_{UV,d}}{V_{U.d}}};$$

(22)

$$D_{C.i.d}={\displaystyle \frac{\sum _{i\in I}{\tau }_{i,d}}{\sum _{i\in I}{\tau }_{i,d}+\sum _{i\in I}{\tau }_{D.i,d}}}; D_{U.i.d}={\displaystyle \frac{\sum _{k\in K}\sum _{i\in I}{\tau }_{i,d}}{\sum _{k\in K}\sum _{i\in I}{\tau }_{i,d}+\sum _{k\in K}\sum _{i\in I}{\tau }_{D.i,d}}};$$

(23)

$$D_{C.j.d}={\displaystyle \frac{\sum _{j\in J}{\tau }_{j,d}}{\sum _{j\in J}{\tau }_{j,d}+\sum _{j\in J}{\tau }_{D.j,d}}}; D_{U.j.d}={\displaystyle \frac{\sum _{k\in K}\sum _{j\in J}{\tau }_{j,d}}{\sum _{k\in K}\sum _{j\in J}{\tau }_{j,d}+\sum _{k\in K}\sum _{j\in J}{\tau }_{D.j,d}}};$$

(24)

$$D_{C.q.d}={\displaystyle \frac{\sum _{q\in Q}{\tau }_{q,d}}{\sum _{q\in Q}{\tau }_{q,d}+\sum _{q\in Q}{\tau }_{D.q,d}}}; D_{U.q.d}={\displaystyle \frac{\sum _{k\in K}\sum _{q\in Q}{\tau }_{q,d}}{\sum _{k\in K}\sum _{q\in Q}{\tau }_{q,d}+\sum _{k\in K}\sum _{q\in Q}{\tau }_{D.q,d}}}.$$

(25)

Crowdshoppers plan to use vehicles based on their interests, which makes it difficult to implement the optimal distribution of VSFs between CMFMCs; therefore, limits should be set on the values of the groups of daily indicators of VSF usage in CMFMCs (e.g., $P_{C.d}\le 1.3;D_{C.i.d}\ge 0.75; D_{C.j.d}\ge 0.82;D_{C.q.d}\ge 0.8)$.

The groups of daily indicators (22)–(25) enable the generation of samples of current and retrospective data necessary for forecasting the use of VSFs for LMPD crowdshipping in CMFMCs, taking into account the influence of seasonal and social factors. The values of the group of the daily indicators of VSF usage for crowdshipping LMPD in CMFMCs allow the prediction of their approximate values the next day and, on this basis, the forecasting of the demand for cargo transportation. Forecasting the VSF demand for crowdshipping LMPD in the CMFMC for the coming day allows for planning changes in its structure and size to enhance cargo transportation performance by redistributing vehicles usage times throughout the day, attracting VSFs from less busy CMFMCs and adjusting cargo transportation tariffs in real time. This approach to describing and predicting the use of VSFs for LMPD crowdsourcing in CMFMCs is applicable provided that it operates normally every day without days off; otherwise, only working days should be considered, noting that Mondays are typically the most active days for parcel delivery.

The group of daily indicators of VSF usage for crowdshipping LMPD in CMFMCs also allows for setting limits on their daily values during specified time intervals. For example, for nighttime, the possible time interval for recording the values of daily indicators is 2 h; for the rest of the day, it is every hour [8]. The distribution of the values of the group of daily indicators of VSF usage for crowdshipping LMPD in CMFMCs during the day shows that the cargo transportation peak is usually observed in the morning and evening before and after working hours. A more uniform use of the VSFs throughout the day is possible due to the tariff policy of crowdshipping LMPD in CMFMCs.

Thus, the average values of a group of daily indicators and their limit values during the day are intended for the current planning of crowdshipping LMPD in CMFMCs [4,8]. The following case study illustrates an approach to identifying the potential of crowdshipping LMPD in CMFMCs as well as its strengths and weaknesses based on the proposed model.

5.3. A Case Study

As a case study, consider a large city with eight CMFMCs with production buildings, CLNs (Figure 1), and current distribution of parcels and VSFs, the initial data of which are presented in

Table 2. The characteristics of the CMFMC buildings and current distribution of parcels and VSFs.

Parameters	CMFMC Numbers								CMFMCs (Total)
	1	2	3	4	5	6	7	8
F	10	10	8	8	6	10	8	6	66
$H_f$	9	9	9	9	7	9	9	7
${\epsilon }_f$	1	1	1	1	1	1	1	1
${\lambda }_f$	1	2	2	1	1	1	2	1
$m_f$	0.8	0.8	0.8	0.8	0.8	0.8	0.8	0.8
$T_f$	1.0	1.0	1.0	1.0	0.8	1.0	1.0	0.8
$w_P$	0.7	0.7	0.7	0.7	0.8	0.7	0.7	0.8
$N_C$	50	101	81	40	34	50	81	34
$N_U$									471
$w_C$	0.8	0.6	0.7	0.8	0.8	0.7	0.6	0.8
$z_C$	0.2	0.1	0.1	0.3	0.4	0.2	0.2	0.3
$G_C$	50	71	65	44	41	45	65	37
$G_U$									418
$a_i$	0.92	0.87	0.9	0.8	0.7	0.9	0.88	0.75
$a_j$	0.8	0.9	0.85	0.8	0.8	0.8	0.85	0.82
$a_q$	0.89	0.92	0.91	0.92	0.92	0.9	0.88	0.92
$b_i$	80	90	70	80	70	70	75	65	600
$c_j$	28	26	22	24	16	26	23	18	183
$l_q$	24	33	31	18	16	16	30	11	179
$S_i$	0.25	0.25	0.25	0.25	0.25	0.25	0.25	0.25
$S_j$	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
$S_q$	2.25	2.25	2.25	2.25	2.25	2.25	2.25	2.25
${\tau }_i$	2.1	1.9	1.7	1.8	1.0	1.8	2.0	1.1
${\tau }_j$	2.2	2.1	2.0	1.9	1.8	2.2	2.0	1.9
${\tau }_q$	3.1	3.0	2.8	2.9	2.2	2.8	2.7	2.5
${\tau }_{D.i}$	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.3
${\tau }_{D.j}$	0.35	0.35	0.35	0.35	0.35	0.35	0.35	0.35
${\tau }_{D.q}$	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
$B_C$	7.7	8.9	7.9	7.6	9.4	7.5	7.2	9.4	65.6
$C_C$	4.4	4.8	4.0	4.3	3.0	4.1	4.2	3.3	32.1
$L_C$	13.4	19.5	19.2	11.0	12.3	9.8	18.6	7.6	111.4
$P_C$	1.02	0.94	0.96	1.04	1.21	0.95	0.92	1.1
$P_U$									1.0
$P_{CB}$	0.31	0.25	0.24	0.34	0.46	0.33	0.22	0.51
$P_{CC}$	0.18	0.14	0.12	0.20	0.15	0.18	0.13	0.18
$P_{CL}$	0.53	0.55	0.58	0.50	0.60	0.44	0.57	0.41
$P_{UB}$									0.32
$P_{UC}$									0.15
$P_{UL}$									0.53

. The values of the groups of daily indicators of VSF usage for crowdshipping LMPD in CMFMCs are presented in

Table 3. Values of the groups of the daily indicators of VSF usage in CMFMCs.

Indicators	CMFMC Numbers								CMFMCs (Total)
	1	2	3	4	5	6	7	8
$V_{CV.d}$	434	809	662	354	350	405	635	319
$V_{UV.d}$									3968
$V_{C.d}$	400	808	848	320	272	400	648	272
$V_{U.d}$									3968
$P_{C.d}$	1.09	1.0	0.78	1.11	1.29	1.01	0.98	1.17
$P_{U.d}$									1.0
$D_{C.i.d}$	0.875	0.864	0.85	0.857	0.769	0.857	0.87	0.786
$D_{U.i.d}$									0.841
$D_{C.j.d}$	0.863	0.857	0.851	0.844	0.837	0.863	0.851	0.844
$D_{U.j.d}$									0.851
$D_{C.q.d}$	0.861	0.857	0.848	0.853	0.815	0.848	0.844	0.833
$D_{U.q.d}$									0.845

. All CMFMCs in this large city are divided into three groups of equal size. The first group is large CMFMCs 1, 2, and 6; the second is middle CMFMCs 3, 4, and 7; and the third is small CMFMCs 5 and 8. The working day in the CMFMCs lasts 8 h. There are no time restrictions for crowdshippers and rental vehicles, but the greatest daily activity of crowdshippers lasts 10–16 h. During seasonal and holiday periods, the working hours of personnel in clusters and crowdshippers may change. To simplify our analysis, we consider only situations in which the ratio of working hours of CMFMC personnel and crowdshippers is constant at $r_C$ ≈ 0.5. The VSF in each CLN parking lot consist of e-bicycles, e-cars from Škoda (Enyaq) or Volkswagen (ID.4), and e-LCVs from Renault (Kangoo Van E-Tech and Kangoo Z.E.) or Nissan (Townstar Van and e-NV200). The size of the VSF in each CMFMC depends on the demand for vehicle sharing and crowdshipping services. The average transportation carrying capacities of the vehicles are as follows: S_i = 0.25 IRT, S_j = 0.5 IRT, and S_q = 2.25 IRT. The value limitations for the groups of daily indicators of VSF usage in CMFMCs are as follows: $P_{C.d}\le 1.3;D_{C.i.d}\ge 0.75; D_{C.j.d}\ge 0.82;D_{C.q.d}\ge 0.8$.

The indicators for the distribution of VSFs in the CMFMCs, presented in Table 2, are associated with two approaches to their use: vehicles rented by users without participating in parcel delivery and those used in parcel delivery by crowdshippers. The objective function for this case study is as follows:

$$\Omega =\sum _{k\in K}(B_{C.k}+C_{C.k}+L_{C.k})\to max,$$

under the following limitations:

$$\sum _{k\in K}(B_{C.k}+C_{C.k}+L_{C.k})\le 209:$$

$$\sum _{k\in K}\sum _{i\in I}{b}_i \le 600:\sum _{k\in K}\sum _{j\in J}{c}_j \le 183:\sum _{k\in K}\sum _{q\in Q}{l}_q \le 179;$$

Numerical solutions using MATLAB R2023a Update 7 (9.14.02674353) were carried out until the redistribution of VSFs between CMFMCs produced the values of the groups of daily indicators of VSF usage in CMFMCs that met the adopted limitations. The obtained results are presented in Table 3. This adjustment in the distribution of VSFs between CMFMCs can be implemented by modifying the current tariffs for crowdshipping services in the appropriate LMPD directions.

The results obtained in this case study indicate the following:

• The characteristics of production buildings and current distribution of parcels and VSFs define the performance of logistics processes related to crowdshipping LMPD, taking into account the finite production capacity of parcel generation in the CMFMCs. These characteristics are used for strategic management and the planning of logistics operations in CMFMCs. The values of the groups of the daily indicators of VSF usage in CMFMCs give an idea of the actual logistics processes during certain periods of the day, throughout the day, and facilitate the creation of a database of daily indicator profiles. The daily indicators of VSF usage can change significantly during the day in real time and are used for tactical management and the planning of logistics operations in CMFMCs. Parameters $w_C$, $z_C$, $a_i$, $a_j$, $a_q$, ${\tau }_i$, ${\tau }_j$, ${\tau }_q$, ${\tau }_{D.i}$, ${\tau }_{D.j},$ and ${\tau }_{D.q}$ should be taken into account when strategically planning logistics operations in clusters as they significantly impact crowdshipping delivery performance.
• Small CMFMCs are primarily located in the central part of a large city with historically established transport communications that restrict e-car and e-LCV traffic; therefore, in small CMFMCs, the share of e-bicycle use from VSFs for crowdshipping LMPD is significantly higher than that in medium and large CMFMCs. Despite their small carrying capacity, e-bicycles are widely used by young crowdshippers for intra-cluster LMPD due to their cheapness, environmental cleanliness, and accessibility. The use of bicycles for crowdshipping LMPD in CMFMCs is expected to increase.
• Cars make the smallest contribution to LMPD crowdshipping in CMFMCs due to their small VSF size and small carrying capacity; nevertheless, rental cars attract drivers from a range of age groups and contribute to their involvement in crowdshipping activities. Most crowdshippers started out as car drivers and then turned their attention to the more favorable conditions of crowdshipping using e-LCVs. Thus, a fleet of passenger cars not only brings benefits to lessors and renters but also contributes to the crowdshipping activity of drivers and to the expansion of the range of vehicles used from the VSFs.
• e-LCVs are the main means for crowdshipping LMPD for both intra- and inter-cluster cargo transportation. They have a high carrying capacity and maneuverability in urban environments with high daily indicators of VSF usage. Their disadvantage is their low passenger capacity, which is compensated for by cars from VSFs, and the potential for downtime while reducing the generation of parcels in CMFMCs.
• The current distribution of cars and e-LCVs between CMFMCs is defined by the influence of customer demand for cashing and crowdshipping services and tends to self-optimize. The distribution of vehicles and e-LCVs between CMFMCs in real time may have more significant deviations from the optimal values.
• The results of this case study showed that the values of the groups of the daily indicators of VSF usage in CMFMCs do not exceed the established limits.

The obtained results provide initial information for monitoring and planning the VSFs use for LMPD crowdshipping in CMFMCs. The organization of ongoing VSF usage monitoring for crowdshipping LMPD in CMFMCs would facilitate the creation of databases containing typical daily indicator values, aiding in cargo transportation planning and performance management.

5.4. Managerial Implications

This study aims to improve the urban mobility of LMPD in CMFMCs by harnessing the potential of crowdshipping and VSFs at CLN parking areas. Using the performance evaluation model for crowdshipping LMPD allows for the creation of daily indicators of VSF usage in each CMFMC, based on which future cargo operations in the CLNs can be planned. The daily indicators of VSF usage in CMFMCs also contain information about the resources used for their delivery (e.g., IRTs, delivery bags, VSFs, the structure of their vehicles, and average delivery times). Other economic (e.g., costs and revenues of stakeholders from the use of VSFs), social (e.g., the degree of satisfaction of manufacturers, CLNs, crowdshippers, and customers in the services provided), and environmental (e.g., emission reductions due to e-VSF growth) aspects may also be recorded. Creating a database of the daily indicators of VSF usage using profiles in CMFMCs is possible with blockchain technology and the platform approach used [1,63]. Such information is vital for creating a bank of best practices for managerial implementation under the uncertainty of parcel deliveries in CMFMCs. The findings of this research enable the formulation of recommendations/best practices for crowdshipping LMPD in smart sustainable CMFMCs, which include the following:

• Daily indicators of VSFs using profiles of information on crowdshipping LMPD in CMFMCs should be collected and analyzed using blockchain technology and a platform approach, recording routes and supply chains, vehicles used, on-time deliveries, and other parameters related to economic, social, and environmental aspects [8,64];
• The use of last year’s and current daily indicators of VSFs, along with profiles of information on crowdshipping LMPD in CMFMCs, enables the rational distribution of IRTs, light e-trucks, and VSFs at CLN parking areas, attracting appropriate crowdshippers to increase urban freight mobility;
• The use of radio-frequency identification (RFID) tags on shipped parcels allows for the collection of data on daily indicators of VSFs, providing information about the nature of the cargo in parcels and its compatibility with other cargo in IRTs and delivery bags, as well as facilitating the automatic identification, tracking, and filling of IRTs [1,65];
• Monitoring and registration of the parcels location and vehicles in real time are achieved through RFID, Global Positioning System (GPS), wireless fidelity (Wi-Fi) systems, video surveillance, cargo weight control, and IoT-Blockchain technology. This information enables the prediction and recording of crowdshipping LMPD times, enhances operational transparency, ensures supply reliability, and creates daily indicators of VSFs using the profiles of logistics processes in CMFMCs [1,8];
• The crowdshipping LMPD performance ratio is an integrated indicator of the economic, social, and environmental effectiveness of green VSFs and may be used to identify best practices for logistics operations within CMFMCs;
• The formation of best practice samples for crowdshipping LMPD from the perspectives of economic, social, and environmental aspects is essential for operational use in typical supply situations;
• The use of recommended routes and sets of last-mile parcel supply chains for crowdshippers, taking into account their planned routes of rented vehicles, aims to engage and motivate crowdshippers’ activities while reducing the mileage of empty vehicles within the framework of the closed-loop supply chain concept. Recommendations on the arrival time of the rented vehicle at the CLN parking area are provided to facilitate parking and subsequent rental. This real-time information support is provided to registered crowdshippers via the PCVSS on their personal smartphones. The main principle of such recommendations is to minimize the cost of resources and time for parcel delivery within the framework of the “just in time” concept [1].

These recommendations/best practices provide operators/managers of CLNs, focal firms (PCVSS owners), and production enterprises with the means to better organize smart management for crowdshipping LMPD in CMFMCs.

6. Discussion

This case study showed that the average trip time of rented vehicles carrying parcel volumes corresponding to their average transportation carrying capacity has a significant impact on the size of VSFs. The average travel time for each vehicle type is a characteristic of the lag (inertia) in VSF redistribution between CMFMCs when their production load changes. The value limitations for the daily indicators of VSF usage in CMFMCs for each CMFMC can be set by considering the actual average trip time of rented vehicles over a specified time period (day, week, month, season). The optimal LMPD routes recommended by the PCVSS help to reduce the average trip time. The best option for travelling between CMFMCs is to rent a vehicle, load it with delivery bags, drive it to the required CLN parking area, unload it, and return it to the renter. For further trips within the same CLN parking area, a new vehicle with less cargo space may be rented for parcel delivery to PLCs within the CMFMC. The daily indicators of VSF usage depend on the season and on weather conditions; however, statistics on the daily indicators of VSF usage allow for effective planning of vehicle use from the VSFs at the CLN parking area for LMPD in each CMFMC.

The adoption of appropriate legislation and referential taxation contributes to the promotion of sustainable crowdsourcing scenarios for LMPD in CMFMCs using VSFs [61]. It is evident that legislative support for transport enterprises that promote the use of green vehicles for crowdshipping LMPD in the CMFMC is a key component of sustainable smart city development. Another factor contributing to the promotion of sustainable scenarios for LMPD in CMFMCs is remuneration management for the provision of crowdshipping logistics services. Increased remuneration may be provided to registered crowdshippers for the use of bicycles for delivering parcels, for repeated participation (during the months/year) in the provision of this type of logistics service, and the implementation of reverse supply chains that reduce empty runs of the VSFs. The established tariffs for crowdshipping LMPD may be flexible and dependent on the performance of parcel generation in CMFMCs and the use of VSFs. Real-time changes in tariffs for crowdshipping LMPD promote more comprehensive use of VSFs, reduce downtime, and intensify the provision of logistics services during holiday periods. The long-term planning of crowdshipping cargo transportation in CMFMCs in large cities is facilitated by the formation of daily indicators of VSFs using the profiles of LMPD during similar time periods from previous years, which enables the timely development and distribution of VSFs and effective decision-making on the management of tariffs for crowdshipping logistics services [4,8]. It is also necessary to analyze the daily indicators of VSFs using profiles of electricity costs, VSF cost maintenance, liquidation value, and commissions in order to plan the renewal of vehicles as well as future operational activities [8,66].

A wide range of drivers from the population of a large city can become registered crowdshippers on the PCSSV by completing training at centers for innovation and lifelong learning (CILL) in CMFMCs and receiving the appropriate certificate [4,19]. Training and testing of the acquired knowledge and skills of future crowdshippers at the CILL are conducted by invited teachers using e-learning technologies with the involvement of experienced crowdshippers. The CILL also retrains crowdshippers in the case of systematic violations of traffic rules and LMPD in the CMFMCs and loss of registration rights on the PCSSV [4]. This approach to crowdshipper training contributes to the development of alternative urban freight logistics, improving the quality of logistics services provided [67].

The peculiarity of CLN parking being located near shopping centers enables the implementation of sustainable scenarios for crowdshipping LMPD, facilitating the organization of shopping trips using VSFs. Employees of CLNs and shopping centers represent another category of crowdshippers. This category of crowdshippers carries out LMPD before or after their work shifts, primarily using rented LCVs for this purpose. Employees of enterprises and entities located in various areas of large cities, including their residential areas, represent the third category of crowdshippers. They also provide LMPD before and after their work shifts, using both cars and LCVs from the VSFs to combine these deliveries with their commutes to and from work. Employees of various enterprises in large cities who provide services to individuals and legal entities represent the fourth category of crowdshippers. This category of crowdshippers conducts LMPD both during their work shifts and after they end, when traveling to service points, using mainly rented commercial vehicles for this purpose. Students and cycling enthusiasts who deliver parcels to the PLCs on bicycles constitute the fifth category of crowdshippers.

The involvement of crowdshipping cyclists in specialized unions, the organization of competitive processes and their comprehensive advertising in the media, the encouragement of the best participants, and the introduction of a rating system for crowdshippers may have a positive impact on the development of this type of LMPD. Such activities may be initiated by CILLs and ATEPs with the sponsorship of CLNs, such as leading providers of the smart sustainable smart logistics services of CMFMCs [1,4]. In CMFMCs adjacent to the historical parts of large cities, the use of bicycles for delivering parcels is the most suitable solution and should be encouraged through increased tariffs for courier services targeting this category of crowdshippers.

The LSITs may also be integrated into an urban luggage storage network, including luggage storage lockers at railway and metro stations, and can serve as urban freight microhubs within the framework of the urban consolidation center concept [68]. The urban luggage storage network may also be used by crowdshippers for LMPD using the railroad and subway. This approach to crowdshipping LMPD will help expand the geography of deliveries as well as the range of public vehicles used. The LSTs and luggage storages within the urban network should be recognizable by crowdshippers in large cities.

7. Conclusions and Future Research

The problem of LMPD in large cities in the era of everyday use of electronic resources for online purchases of goods and products is one of the main problems in urban freight logistics. Some studies link the solution to this problem with the use of parcel lockers and their integration as transfer points for customers and crowdshippers. This approach to solving the LMPD problem is now becoming universal in large cities [18,69]. The presence of CMFMCs in large cities, in which parcels are produced for the urban population, organizations, and enterprises, brings its own specific considerations to solving the LMPD problem.

This study presents an integrated approach to improving LMPD performance in CMFMCs under uncertainty by involving crowdshippers and VSFs in CLN operations and interfacing them with networks of parcel lockers and luggage storage facilities in large cities. Sustainable scenarios for inter- and intra-cluster crowdshipping LMPD utilize PLPs, PLCs, LSFTs, and LSITs as transfer points for customers and crowdshippers. Parcel flow separation according to delivery directions to the PLPs, PLCs, LSFTs, and LSITs streamlines the execution of logistics operations by crowdshippers at the CLN parking area. The involvement of registered crowdshippers and VSFs enables the provision of LMPD and the unloading of the CLNs in CMFMCs. The development of crowdshipping LMPD in CMFMCs enables the complete redirection of parcel flows through the networks of VSFs, PLPs, PLCs, LSFTs, and LSITs. Integrating the LSIT network of CMFMCs with luggage storage lockers at railway and subway stations expands the possibilities for crowdshipping LMPD in large cities.

A performance evaluation model for crowdshipping LMPD in CMFMCs was proposed herein, which considers their finite production capacity for parcel generation and the throughput of VSFs located at CLN parking areas. The findings provide insight into the crowdshipping LMPD performance in CMFMCs using VSFs and the possibilities of increasing the throughput and reducing vehicle downtime by distributing them between CLN parking areas and adjusting their structure. The proposed model enables the planning of short- and long-term logistics operations with specified performance indicators for the use of VSFs in CMFMCs.

This study has limitations that present opportunities for future research. First, the results and conclusions of this study may be limited by the use of the same types and ratios of vehicles at CLNs and VSF sizes corresponding to the finite production capacity of parcel generation in each CMFMC. Since the intensity of parcel generation in CMFMCs varies based on consumer demand and supply uncertainty, redistributing VSFs between CLN parking areas may be appropriate to meet actual needs. It is possible to conduct a study of the redistribution of VSFs between CLN parking areas, considering the actual production capacity of parcel generation in each CMFMC and the ranking of loss factors associated with such logistics operations. Second, this study touches on certain issues related to the use of IoT-Blockchain technology to create a database of the daily indicators of VSFs using profiles with information on economic, social, and environmental indicators of crowdshipping LMPD in CMFMCs using VSFs. These issues are also of interest for further research into logistics activities in CMFMCs.