1. Introduction
The construction industry is important for national economics and urbanization. The construction project is often characterized by a long duration, a complicated environment, and a large number of safety risk factors [
1]. The internal and external environments in which construction projects operate are becoming increasingly volatile and uncertain due to the frequent occurrence of high-risk events such as financial crises, international conflicts, and natural disasters [
2]. During the long-term construction process of a construction project, the complex working environment creates potentially high risks, such as schedule delays (the actual completion date of one or more items of work during the execution of the project is later than the completion date specified in the plan, resulting in an extension of the overall contract period), cost overruns (the financial resources allocated to an enterprise exceed the budgetary limits set for the project), and quality issues (the quality of projects does not meet the specified requirements or expected objectives during the implementation of the project or after it has been put into use). For example, COVID-2019 has led to setbacks in production for most construction companies, and adverse conditions such as material shortages and resource conflicts have led to project cost overruns, delays, and even extended work stoppages [
3]. It is now widely acknowledged that this kind of disruption can be a serious impediment to project delivery. To manage the impact of these disruptions, project managers must make decisions such as adjusting the work plan, improving communication and cooperation between parties, and reallocating resources to ensure construction project success [
4].
Many studies have been carried out in industry and academia to increase the project’s capabilities in addressing risk or disruption [
5]. The industry has developed a number of standards and specifications to guide project risk management practices. For example, the International Organization for Standardization (ISO) has published a series of standards related to risk management, such as ISO 31000 “Risk Management-Principles and Guidelines” [
6], which provides a systematic approach to help organizations identify, assess, and respond to a variety of risks, including risks in construction projects. Academics have also conducted a lot of research to explore ways to improve the risk resistance of projects and have proposed various methods and models for risk identification [
7,
8,
9], risk assessment [
10], and risk communication [
11,
12], to help project managers better understand and manage various risks of projects [
13]. Against this backdrop, scholars in the field of project management have begun to explore why some projects struggle to survive in the face of adverse circumstances, while others are able to turn the corner. Then, scholars developed the concept of ‘project resilience’ to explain such differences [
12]. Resilience originated in ecology, where it was defined as the ability of ecosystems to withstand damage [
12]. In the project management field, resilience refers to an individual or a project’s ability to develop and apply its capabilities to withstand adverse disruptions, recover from crises, and anticipate unknown risks [
12]. Improving project resilience has become a goal pursued by many construction companies to carry out project practices. Projects with higher resilience can quickly adapt and respond to environmental changes, maintain system stability and continuity, and improve project success and performance.
Besides scholars having introduced the concept of resilience into the field of construction projects, researchers have started to develop a theoretical framework for project resilience, examining its components, influencing factors, and assessment for improvement [
14]. However, there is currently no consensus on how to define and assess project resilience [
15]. Assessing project resilience is frequently influenced by subjective factors; thus, it is difficult to objectively and robustly reflect the level of project resilience [
16]. Additionally, most resilience assessment models are model-driven, with fewer studies focusing on data-driven approaches. Thus, this paper intends to propose a more accurate method to assess project resilience, including developing a quantitative data-driven model and establishing objective resilience assessment criteria. Due to the Reference Class Forecasting (RCF) technique offering an objective approach by considering an external project perspective and the Radial Basis Function (RBF) neural network excelling in fitting nonlinear patterns, especially with small sample sizes, this paper constructs a model by combining the RCF technique and RBF neural networks to forecast project performance, illustrate the changes in performance levels during the disruption and recovery phases of a project, and thus quantitatively assess project resilience. Assessing resilience can provide a theoretical basis for project decision-makers, such as adjusting the work plan, improving communication and cooperation between parties, and reallocating resources to ensure construction project success [
4].
To summarize, the goal and objective of this paper are to develop a data-driven approach for assessing project resilience. To this end, this paper combines RCF and RBF to construct a theoretical model that can forecast project performance levels and then assess project resilience on this basis. The proposed model is validated with 64 construction projects to demonstrate its feasibility and applicability. The model in this paper can be effectively used to assess project resilience, serve as a bridge for future research, and provide clear guidance for project management.
The remainder of this paper is organized as follows: The following section provides an overview of resilience definitions, as well as resilience assessment, RCF technique, and RBF neural network applications. Subsequently, based on the RCF technique, an RBF neural network model is established to forecast project performance levels and assess project resilience. Then, the model is validated using 64 construction projects that have faced disruptions from various sources. Finally, we discuss the theoretical contributions and practical implications of this paper.
2. Literature Review
In this paper, the traditional literature review method is employed to identify relevant literature. A search is conducted in Web of Science using the topic item ‘project resilience’ or ‘assessing project resilience’ or ‘resilience assessment’ or ‘quantify resilience’, and the keywords ‘resilience assessment’ or ‘measure resilience’ or ‘quantify resilience’ or ‘RCF technique’ or ‘RBF neural networks’. This retrieved 337 articles. Subsequently, the same method is employed to identify 70 articles on Elsevier Science Direct and 306 articles on Engineering Village. Duplicate articles from the three data sources are removed, and then articles unrelated to construction projects and those with missing information are excluded. The final number of relevant articles obtained is 40, as shown in
Table 1. In this section, we will discuss the concept of resilience, the assessment of resilience, the RCF technique, and RBF neural network applications in extant literature.
2.1. Definition of Resilience
The concept of resilience was originally derived from the Latin word “resilio”, meaning to return to one’s original state. Initially applied to physics as engineering resilience, the concept was later introduced to ecology by Holling in 1973 [
17]. In common definitions, resilience is often viewed as a static capacity or dynamic process that includes the potential ability of a system to anticipate, avoid, and adapt to environmental shocks [
18]; the ability of a system to continue functioning in the face of a disruptive shock [
19]; or the ability to withstand a shock and to recover from it [
20,
21].
The concept of resilience has then been widely used in physics, material science, psychology, environmental science, and emergency management [
22]. In the field of project management, Geambasu et al. [
23] first proposed the concept of project resilience, which is considered to be the ability of a project to withstand and continuously adapt to change. Then, more and more scholars proposed different concepts of project resilience, which can also be generally categorized into two major kinds: process perspective and capability perspective [
24].
(1) From a process perspective, project resilience is considered throughout the project and focuses on the long-term development of the project. For example, Wang et al. [
25] adopt a process perspective to understand and construct project resilience. They define project resilience as the ability to withstand shocks, cope with challenges, and recover. Turner and Kutsch [
26] call for the development of the concept of project resilience and mention that it involves anticipating, understanding change, and planning for scenarios to minimize losses and adapt to new realities.
(2) From a capability perspective, project resilience is often linked to “resistance”, “adaptation”, “rebound”, and “learning” [
22]. For example, Blay et al. [
27] conceptualize project resilience in their empirical study of engineering projects as the ability to prepare for, respond to, and mitigate the impacts of disruptions to ensure successful project delivery. Zarghami et al. [
15] see project resilience as a set of interrelated capabilities that projects need before and after a disruption occurs, and that should be complemented by the development of preparedness capabilities to recover from the disruption before it becomes apparent. The process perspective definition is more applicable when looking at the full life cycle of a project, whereas the capability perspective is more concerned with the state of recovery of a project after it has been subjected to a disruption. The research perspectives used vary depending on the focus of the research.
2.2. Assessing Resilience
The inadequate performance of traditional project risk management has prompted a growing demand for research on project resilience. However, the absence of a unified theoretical framework and assessment methodology has resulted in a limited number of studies adopting the concept of “project resilience” [
22], in comparison to those on organizational resilience. Project resilience assessments can be broadly categorized, including subjective and objective approaches [
22].
(1) Subjective assessment methods are employed to identify and quantify resilience at the individual and organizational levels [
16]. These methods include self-assessment, expert assessment, and group discussion, which provide insights into respondents’ perceptions and assessments of resilience levels, such as the ability to cope with stress and challenges, adaptability, and other aspects [
28]. Modeling studies can typically be conducted using techniques such as fuzzy analysis or Bayesian networks [
29]. However, studies based on such methods are inherently subjective because they are not based on specific historical data but rather on expert experience. These assessment methods rely excessively on the a priori knowledge of the experts [
30], and at the same time, due to the differing experiences of each expert, there is a certain cognitive bias, and the scoring criteria provided are different, which results in a certain degree of bias in the assessment of project resilience.
(2) An objective method of assessing project resilience can be achieved by quantifying various indicators such as resource reserves, emergency response capacity, speed of recovery, and other attribute data and indicators [
7]. These indicators are obtained through historical data, statistical analysis, and other means, such as data on project schedule delays, cost overruns, and disaster losses [
31]. An indicator system is typically developed around the concept of resilience, followed by a comprehensive assessment using quantitative methods such as entropy weights [
32], hierarchical analysis [
33], TOPSIS [
34], Monte Carlo simulations [
35], and fuzzy logic systems [
36]. Monte Carlo simulation and fuzzy logic are two different, but both play an important role in dealing with complex and uncertain problems. Furthermore, project resilience assessment may be based on the performance level change curve of a project following a disruption [
15]. From this curve, various attributes may be extracted, including the magnitude of the decrease in performance level, the degree of recovery, the length of recovery, the speed of recovery, and the average cumulative consequences, which may be subjected to a specific mathematical operation (e.g., multiplication) [
10,
32,
37]. While these methods provide an accurate assessment of project resilience, they do not provide forecast results of future trends in the project.
2.3. RCF and RBF Neural Network Applications
In the context of investment decisions, the accuracy of forecasts of the cost and schedule of a project is of great importance. In construction projects, techniques such as BIM (Building Information Modeling) and RCF (Reference Class Forecasting) are often employed in order to forecast project costs and schedules [
38]. However, it should be noted that BIM can forecast project costs and schedules [
39], but that it relies on the subjective judgment of the project manager, which can lead to cognitive bias. Consequently, Servranckx [
38] uses the external perspective—also known as the RBF technique—which was demonstrated to possess a high degree of accuracy in the forecasted results of project costs. Flyvbjerg [
40] provides an illustrative example of RCF in practice; that approach was utilized to forecast the costs associated with the Edinburgh Tram. Batselier and Vanhoucke [
41] conducted an empirical evaluation of the method by applying it to a dataset comprising twenty-four real-world projects originating from the construction industry. Their findings indicated that the RCF technique is more accurate than traditional forecasting methods and provides more precise forecasts. Consequently, RCF techniques are now being employed in a multitude of contexts, including planning, project management, cost estimation, and strategic management [
42].
RBF (Radial Basis Function) neural network is a frequently used model in artificial neural networks [
43]. Moody and Darken [
44] were the first to try to introduce the principle of RBF function in the design of artificial neural networks, which eventually constituted the RBF neural network. A RBF neural network is composed of an input layer, a hidden layer, and an output layer. The activation function of the hidden layer uses the radial basis function, which weights the input by radial symmetry with the center in the input space to obtain the output of the hidden layer neurons [
45]. The radial basis function is known for its strong nonlinear fitting ability and its ability to capture complex nonlinear relationships. As a result, the RBF neural network is highly adaptable when it comes to dealing with nonlinear problems. Although Monte Carlo simulation and fuzzy logic also offer significant advantages when dealing with complex and uncertain problems, they each have some drawbacks. Monte Carlo simulation requires a large number of random samples for simulation and is computationally slow [
35]. Fuzzy logic, on the other hand, lacks adaptive and self-learning capabilities, which means that they may not adapt well to environmental changes or the emergence of new data [
36]. Meanwhile, RBF neural networks are particularly effective when trained on small sample datasets, as they can achieve better generalization performance with less data. In the event that the quantity of data are considerable in size or the data characteristics are more intricate and diverse, the RBF model may be more susceptible to overfitting as a consequence of the complexity of the data distribution. Additionally, its strong generalization ability means that the performance on the training set tends to translate well to the testing set, allowing for more accurate forecasted results when dealing with unknown data. There have been many scholars applying RBF in different fields, such as construction estimation, schedule forecast, and the daily schedule completion rate of construction projects [
46]. For example, Li et al. [
47] used neural networks to help tunnel engineers estimate the productivity of the next cycle, thus improving productivity. Lesniak and Juszczyk [
48] identified the project type, project geographic location, and duration as the key influencing factors and used neural networks to forecast the project overhead costs.
2.4. Research Gap
The pursuit of greater project resilience has become a key objective for projects. Projects with high resilience are able to adapt and respond rapidly to environmental changes, maintain system stability and continuity, and thereby enhance the success rate and performance level of the project. This, in turn, provides decision-makers with the information they require to make informed decisions. In the current highly competitive market environment, assessing and enhancing construction project resilience has become one of the important means for construction enterprises to obtain competitive advantages in the market. However, due to the lack of a unified theoretical framework and practical path, the connotation and measurement of project resilience are not uniform. Furthermore, only a relatively small number of studies have assessed project resilience, and existing project resilience metrics are often influenced by subjective factors, making it difficult to objectively reflect the level of project resilience. And most of the existing resilience assessment models are model-driven, with fewer studies on data-driven.
To address this research gap, this paper defines project resilience, combines the RCF technique and RBF neural network to construct a model that forecasts the project performance level, and then assesses the level of project resilience by calculating the ratio of recovery to loss of project performance, with a view to providing assistance to project decision makers.
6. Conclusions
Construction projects are essential for the continued functioning of modern society, as they play a critical role in improving the country’s economic status. However, these projects face inherent complexity and interdependency that hinder their performance and cause various disruptions (such as delays to schedules and cost overruns). These disruptions can ultimately result in long-term consequences, including legal claims, disputes, and dissatisfaction among stakeholders. In order to mitigate the impact of project disruption, it is necessary to assess the level of project resilience. Nonetheless, while assessing project resilience is critical for supporting decision-making, prior research seldom employs theoretical models to tackle this problem. The absence of an objective assessment of project resilience and its influence on the project implementation process limits the development of high-quality construction projects. This model overcomes the limitations of subjective judgments and intuition. This paper presents an approach to project performance forecasting. It combines the RCF technique and RBF neural network to construct a model that uses completed historical project data as a database for training and validation. This approach enables the assessment of project resilience with greater accuracy.
The research in this paper is not without limitations. An important limitation lies in the construction of the RBF neural network, which is based on a limited dataset consisting of 64 construction projects. This information set, although representative, is not sufficiently comprehensive to cover the large number of project types that exist in the construction industry. Therefore, the generalizability of the findings may be limited to projects that are very similar to those in the dataset. Given the inherent complexity and variability of construction projects, there is a need for a broader and more comprehensive dataset to fully reflect project types and their unique characteristics. In addition, the assessment model constructed in this paper only focuses on indicators in terms of cost, duration, and risk level of the project, and the results of the study have some limitations.
Despite these limitations, this study opens several avenues for further research. Firstly, the mathematical model developed in this paper has wide applicability and has the potential to forecast the performance of various construction projects. Building on this foundation, future research can extend the functionality of the model by incorporating additional metrics such as stakeholder satisfaction and project effectiveness. These indicators would provide a more comprehensive view of project performance and could enhance the comprehensiveness of the forecasted results. In addition, incorporating long-term indicators into the model can provide more insight into project resilience and its evolution over time. This is particularly useful for assessing the sustainability and long-term success of construction projects. In addition, exploring the use of advanced machine learning techniques and algorithms could further refine the forecasted capabilities of the model, potentially leading to more accurate and reliable performance forecasts. In conclusion, there are substantial opportunities for future research to expand and extend the results of this study, contributing to a more nuanced and comprehensive understanding of the resilience of construction projects.