1. Introduction
Construction has always been considered one of the country’s most important sectors. Large-scale construction projects are complex and multidisciplinary. Under impacts in the big picture, the traditional management mode is increasingly restricting the development of construction enterprises due to fierce competition and professional differentiation [
1]. As traditional labor-intensive enterprises, it is becoming increasingly difficult for any construction company to survive alone. As construction projects are often large and complex, contractors often need to integrate subcontracting of effective resources to complete some parts of the project [
2,
3]. Therefore, establishing a sustainable working relationship between project managers and subcontractors, identifying the root causes of key obstacles, and addressing and dealing with them through the use of all necessary techniques is key to project success. It is an effective way to create a sustainable cooperation relationship for pooling finances, technology, skills and specializations [
4,
5].
Due to the requirements of specialization, resource integration and risk dispersion, for a large and complex project the number of contract packages divided by contractors can be as many as dozens or even hundreds [
6,
7]. With the differentiation of specialties, the management mode between main contracting and subcontracting is also changing gradually [
8,
9]. The reasons are as follows: From the perspective of government, the state has vigorously advocated the contracting model in recent decades. Increasingly, Engineering Procurement Construction (EPC) and Build-Operate-Transfer (BOT) projects are being undertaken on the market [
1,
10]. For the corresponding policy call and market demand, the project delivery model through mutual cooperation between contractors, professional subcontractors and labor subcontractors has gradually formed [
11,
12]. From the perspective of market demand, with regard to projects that are more and more complex, larger and larger, and have more and more strict construction-period requirements, it is often difficult for contractors to successfully complete the delivery by themselves [
13]. For projects with complex construction techniques and high requirements for professional levels, contractors may not have the corresponding construction capabilities [
2,
14]. Thus, they need to invest a lot of manpower and material resources, and the “input-output” ratio is not high [
13,
15]. Therefore, the contractors often transfer this part of work through subcontracting and improve their own core competitiveness through subcontracting management and coordination. From the perspective of major project stakeholders, the owners have higher requirements for project quality and degree of specialization [
16,
17]. Some technical problems in the project must be completed by professional subcontracting. To a greater extent, as for the contractor, transferring risks and project workload through subcontracting can reduce their own burden, streamline the project team and protect their own interests. For professional subcontractors and labor subcontractors, focusing on a specific segment can improve their market position and core competitiveness in this area [
3,
18]. Through the influence of the above three points, the construction industry has gradually changed from the traditional mode to the contractor-led project delivery management mode marked by cooperation between the general contractor and subcontractors [
1,
19,
20].
The importance of the relationship between general contractor and subcontractor in engineering projects is becoming more and more prominent, and many scholars have studied it. However, while most studies focus on the cooperative behavior of subcontractors [
21,
22], it is important to note that the cooperative behavior is largely determined by the cooperative intention. Therefore, it is necessary to pay attention to the long-term cooperation intention of general contractors and subcontractors. Since the general contractor plays a dominant role in the sustainable cooperative relationship between the general contractor and subcontractor, this study intends to be grounded on the general contractors’ position to develop such a relationship. As for the initial cooperation of general contractor and subcontractor, past experiences involving reputation and workability will provide more information and a basis for the general contractor to select subcontractors. [
23,
24]. Using the extended theory of planned behavior (TPB) as a theoretical framework, this study explores what factors affect the contractor’s choice of long-term cooperation and how to achieve the cooperation intention with subcontractors [
25,
26].
From the perspective of theoretical significance, this study first improves the existing literature by comprehensively identifying the factors that affect the long-term cooperation intention of contractors and subcontractors. Second, based on the TPB, an influence model is constructed to enrich the theoretical system of subcontractors and contractors. Practically, this study was useful in helping the general contractor select a partner, while also providing suggestions for subcontractors to improve their work.
The remaining sections of this paper are organized as follows.
Section 2 offers a review of the literature on relationships between general contractors and subcontractors and the TPB.
Section 3 describes the theoretical framework and research hypotheses.
Section 4 describes the design of the survey questionnaire and data collection. The results of the data analysis are presented in
Section 5.
Section 6 addresses the key findings from this analysis and research deficiencies. In the end, conclusions are presented along with future research directions.
4. Methodology
Structural equation modeling (SEM) is used to test the proposed hypotheses. SEM analysis is a measurement technique that enables complex causal links between sample data to be expressed in terms of the corresponding model equations and to be measured and analyzed. SEM is therefore particularly suitable for testing predictive and extended theoretical models. In this study, a two-step testing approach was used to first assess the reliability and validity of the measurements included in the current study and then test the hypothesized relationships.
4.1. Questionnaire Design
This study intended to collect data by combining online and offline questionnaires. In order to ensure the questionnaires’ quality, a pilot study was conducted by inviting ten experts working as general contractors before beginning a large-scale distributing of questionnaires. The preliminary questionnaire can determine whether the indicators are in line with an actual situation and miss or repeat questions. The formal questionnaire includes three parts: (1) background information of respondents, including their personal project experience; (2) background information of cooperation experience, which mainly includes length and number of cooperation, etc.; respondents were asked to answer the questionnaire considering the background of the subcontractor in the most recent project they were involved in; (3) the measurement of the general contractors’ long-term cooperation intention using each variable in the expanded planned behavior theory.
Based on the context of the general contractors’ intention to foster a sustainable cooperative relationship with subcontractors,
Table 1 displays the measurement methods for each variable. The questionnaire consists of five constructs and 22 scale items, including five measures of attitude, five measures of subjective norms, five measures of perceived behavioral control, four measures of past experience, and three measures of long-term cooperative intention. A five-point Likert scale was used to assess the items, and respondents were asked to give a rating of 1 to 5 on each item (1 = strongly disagree, 3 = agree, and 5 = strongly agree).
4.2. Sampling and Data Collection
This study intends to explore the long-term cooperative intention between contractor and subcontractor. Directional screening of respondents can ensure the availability of questionnaire data. Therefore, this study issued questionnaires to general construction contractors with contracting experience. Between June 2021 and December 2021, 215 questionnaires were collected, of which 165 were considered valid. In this instance, the logical errors and questionnaires with invalid results have been eliminated and cleaned. The questionnaire validity rate was 76.74%. The participant’s IP address is limited to a single submission in order to prevent the same person from submitting the same questionnaire more than once.
6. Discussion and Implications
The purpose of this research is to understand general contractors’ long-term cooperative intentions with subcontractors and the factors influencing those intentions. The TPB-based integrative conceptual model was developed in order to clarify how subjective and objective elements affect the general contractor’s long-term cooperative behavior. In general, the conceptual model accounts fairly well for the long-term cooperative behavior of general contractors. Research hypotheses were fairly validated.
6.1. Impacts of Attitude, Subjective Norms and Perceived Behavior Control on Long-Term Cooperation Intention
The results of hypothesis testing (see
Table 6) reveal that attitude (β = 0.447, t = 5.727), subjective norm (β = 0.328, t = 4.331) and perceived behavioral control (β = 0.542, t = 6.972) go hand in hand with the general contractors’ long-term cooperative intention positively and significantly, supporting H1, H2 and H3. This result is consistent with the findings of Xie et al. [
58], who applied the TPB to optimize a healthy building-rating system, thereby emphasizing the importance of attitudes, subjective norms, and perceived behavioral control on staff health-related behaviors. This finding suggests that increases in the characteristics of attitudes, subjective norms, and perceived behavioral control may increase the likelihood of long-term general contractor cooperation. This finding suggests that increasing characteristics such as attitude, subjective norm, and perceived behavioral control may enhance the likelihood of the general contractor’s desire to cooperate over the long run.
As previously predicted, perceived behavior control actively contributes to general contractors’ long-term cooperative intention in the context of partnerships between general contractors and their subcontractors. The results of this study support the findings of Zheng et al. that perceived behavioral control facilitates behavioral intentions [
78]. The results also show that strong self-perception of contractors’ long-term cooperation has a significant influence on their willingness to cooperate with subcontractors. Furthermore, it has been confirmed that perceived behavioral control behavior intention has significant correlation to long-term cooperation with subcontractors. Five items were used to measure perceptual behavior control, including interface division, division of rights and responsibilities, communication ability and subcontract management reflecting general contractors’ main management capability configuration applying to subcontractors. This finding suggests that general contractors should divide subcontract interfaces reasonably and specify responsibilities and rights clearly. In the context of long-term cooperation intention, it requires good communication channels for resolving conflicts between general contractors and subcontractors. Rich management skills and experience are also needed for general contractors.
Consistent with the hypothesis, attitude also significantly influences general contractors’ long-term cooperation intention. This is similar to Gloukhovtsev’s findings that behavioral attitudes have a significant effect on the intention of ethical consumer behavior [
79]. General contractors believing in the value of cooperation and achieving high-quality subcontracting services tend to be more willing to establish long-term cooperation with the subcontractor. Five items were used to measure attitudes, mainly including the general contractor’s satisfaction with the subcontractor and the value the subcontractor can provide for the general contractor. Thus, H1 was supported in this context. Hence, the satisfaction, value recognition and trust of general contractors in subcontractors was important.
Subjective norms also positively influence general contractors’ long-term cooperation intention. This finding is similar to Phua’s study, which concluded that influences from internal firms, peer competitors, and policies can drive contractors to develop a willingness to cooperate [
80]. It means that when general contractors determine whether to establish a long-term cooperation relationship with subcontractors, the greater the pressure or expectation from the surrounding environment, the greater the intention to cooperate with subcontractors for the long term. However, analyzing data reveals that subjective norms were less influential than perceptual behavior control and attitudes. Five items were used to measure subjective norms, which mainly include legal norms, policy requirements, owner requirements, and pressures or expectations from company or similar projects. The selection and management of general contractors among subcontractors were restricted by laws and policies, because the construction industry involves many parties and connects with public interest. Subcontractors not only need to obtain qualifications, but also comply with laws and regulations to perform subcontracting behavior. At the same time, general contractors’ enterprise systems and the project owner may also put forward requirements regarding the selection of subcontractors. As a result, general contractors would be affected by these factors when they choose long-term cooperation partners.
In summary, perceived behavioral control, attitude and subjective norms all positively influence general contractors’ long-term cooperation intention.
6.2. Impacts of Past Experience on Attitude, Subjective Norms and Perceived Behavioral Control
Hypothesis testing results show that past experience positively correlates with attitudes (β = 0.157, t = 2.377) and perceived behavioral control (β = 0.467, t = 6.472), which verifies hypotheses 4 and 6. Consistent with prior studies [
5,
23,
81], past cooperating experience is an efficient predictor of attitude and perceived behavioral control, which indicates that the more past experience in cooperating there is between a general contractor and subcontractor, the more active the general contractor will be in building a long-term cooperation relationship with subcontractor, and their subjective perception ability to cooperate with subcontractor will also be stronger.
The data analysis shows that past experience has a greater positive role in perceived behavioral control and attitude, which is consistent with previous research findings and fits with the characteristics of the construction industry [
19,
82]. Two aspects that measure past experience are industry reputation accumulated by subcontractors and the general mutual impression of contractors and subcontractors derived from cooperation in the past. The cooperation between general contractors and subcontractors is a process of continuous run-in and adaptation. It is necessary to constantly balance the needs, goals and capabilities of both sides and constantly revise the communication and coordination mode between both sides. If general contractors have enough past cooperation experience with subcontractors, the cooperation skills and ability of both sides are bound to be improved, and general contractors will be more active in establishing long-term cooperation with subcontractors too.
However, Hypothesis 5 is not supported by the data analysis results. Past experience has very little bearing on subjective norms (β = 0.132, t = 1.235) which deviates from the original expectation and is inconsistent with similar findings from previous studies [
68]. This difference may be due to the fact that in the construction industry, subjective specifications of items are actually objective and include legal requirements, policy specifications, and company systems. Past experience deals more with subjective aspects and has limited influence on these objective factors. Therefore, Hypothesis 5 is not valid.
6.3. Theoretical Implications
Two major theoretical contributions of this study are listed below. First, although TPB has been successfully implemented in different contexts, such as bike-sharing, e-learning, and waste management, few studies apply the theory of sustainable cooperative intention relationships. This study utilizes the TPB to comprehensively identify the factors that influence contractors’ long-term partnership intention with subcontractors. Second, this study expands the literature on contractors’ long-term intention to partner with subcontractors by adding the variable of past experience to take into account the reputation and business capabilities of subcontractors.
6.4. Practical Implications
This study presents important practical implications. The results of the study can be used to select the long-term subcontracting partners and encourage the contractor to prepare adequately at the outset and to organize the project as a whole. Hence, the preparatory work is very significant for the final success of the project. At the same time, the terms of the contract can be adjusted flexibly in accordance with the situation of subcontracting, so as to protect their own interests and the success of the project to the greatest extent. Subcontractors, in turn, can better understand the selection preferences of general contractors, and in future cooperation try their best to cater to the selection criteria of general contractors, so as to improve their core competitiveness, provide references and suggestions for themselves to maintain and improve the long-term cooperation intention and enhance the degree of the development of specialization.
6.5. Research Deficiencies and Prospects
This study introduces mature planned behavior theory to carry out research on the long-term cooperation intention between general contractors and subcontractors. Although this research has theoretical innovations and practical value, it also contains defects limited by subjective and objective conditions. It is hoped that these shortcomings can be corrected in the follow-up research:(1) Constrained by the respondents to questionnaires, most of the data comes from domestic general contractors, such that the conclusions of this research can explain only the formation mechanism of long-term cooperation intention of Chinese general contracting enterprises. In future research, similar research methods can be used to compare and analyze cases in different countries by collecting data from foreign general contractors and combining those cases with models in the overseas background. (2) Many employees participate in the construction industry in complex environments. In accordance with the specific characteristics of construction, this research extends planned behavior theory and introduces the variable of past experience so as to obtain a good hypothesis verification. However, the model still has room for improvement, which is also an issue that needs to be considered in follow-up research. (3) Long-term cooperation intention of the general contractor may be influenced by factors such as project scale, project complexity, project procurement mode and so on. In follow-up studies, we can view these factors as moderator variables to research and compare research differences in different contexts. (4) From the point of view of general contractors, this paper researched their long-term cooperation intentions with subcontractors. However, cooperation is the result of mutual negotiation. Despite the fact that the construction sector is a “buyer’s market,” it is still important to take the subcontractor’s intentions into account. Future research should do this better.
7. Conclusions
How to enhance the cooperation intention between general contractor and subcontractor and how to improve the relationship between both is an important research proposition in the field of construction. This paper seeks to explain the formation mechanism of their long-term cooperation intention from the perspective of a general contractor and puts forward corresponding suggestions based on research results in the hope of making more contributions to the theory and practice of subcontracting management, promoting long-term partnerships and improving subcontracting management.
Through analyzing data of the extended planned behavior theory model, this research obtains the formation mechanism of the long-term cooperative intention of general contractors, thus further providing theoretical basis for general contractors when they choose long-term partners and suggestions for subcontractors to improve their business. Conclusions from verifying the assumptions of the model are listed below: (1) In the connection between the general contractor and subcontractor, perceived behavioral control has the greatest impact on the general contractor’s long-term cooperation intention. The stronger the general contractor’s self-awareness of long-term cooperation with subcontractors, including interface division, division of rights and responsibilities, communication ability and subcontract management, the stronger the willingness of the general contractor to establish a long-term cooperation with the subcontractor. (2) Attitude contributes to the general contractor’s intention to cooperate in the long term. The more positive the general contractor’s evaluation of the partnering subcontractor, the stronger the general contractor’s willingness to establish a long-term partnership with the subcontractor. The evaluation includes the general contractor’s satisfaction with the subcontractor and the subcontractor’s ability to provide a more beneficial value to the general contractor. (3) Subjective norms positively impact the general contractor’s long-term cooperation intention. That is, when the general contractor determines whether to build a long-term cooperation with a subcontractor, the greater the pressure or expectation from the surrounding environment—which mainly include legal norms, policy requirements, owner requirements, and pressures or expectations from company or similar projects—the more inclined the general contractor will be to cooperate with the subcontractor for a long time. (4) Past experience, specifically the industry reputation accumulated by the subcontractor and the general impression of the general contractor and subcontractor derived from past cooperation, positively influences attitude and perceived behavioral control, which in turn affects the general contractor’s intention to work with the subcontractor in the long term.