Determining the Factors Influencing Construction Project Management Performance Improvement through Earned Value-Based Value Engineering Strategy: A Delphi-Based Survey

Abstract

Proper planning and management of construction projects have long been regarded as a necessity. The ability to make sound decisions and solve problems using appropriate performance reports related to the project implementation process are the two most key factors in controlling the performance of construction project management. Even though these factors considerably contribute to controlling precise project performance, previous research has failed to investigate them to their fullest potential. Therefore, this research seeks to fill the existing gap by determining the influential factors on construction project management performance through earned value-based value engineering strategy. In this line, a comprehensive literature analysis was undertaken to extract the influential factors on construction project management performance. Then, three rounds of a Delphi survey were conducted to consolidate the influential factors. There were a total of 39 factors that were grouped into four categories. The identified influential factors were then evaluated through the analysis of quantitative data. The findings showed that the dimension of “Engineering economics” was ranked first in terms of importance, followed by “Project management performance”, “Value engineering approach”, and “Earned value management” at the second to fourth ranks, respectively. The overall ranking of the factors placed “Project Stakeholder Management” in the first position and “Project Management Software” in the bottom place. It is anticipated that the key findings and effective recommendations of this study will considerably contribute to the improvement of decisions on project planning and improve the performance of construction project management while enhancing different stakeholders’ understanding of the most influential factors on the performance of construction project management.

1. Introduction

The project beneficiaries are the people and organizations involved in the project or factors that are somehow influenced by the project’s activities and have ownership, right, or interest in the project or can claim in this regard [1]. Project implementation success requires identifying the beneficiaries and their demands in the project life cycle. The most fundamental mission of project management in determining how project management works is to establish commitment and responsibility toward the schedule, preventing project delays and related costs [2]. Project division into smaller components and finally activities facilitate its management and control, ultimately preventing project delays but increasing the total cost [3]. In the project management literature, quality, cost, and time are the main factors of successful project performance [4]. Based on the Project Management Body of Knowledge (PMBOK), the project management process includes initiating, planning, executing, monitoring and controlling, and closing, and scope management includes scope, quality, cost, and time objectives [5]. These processes interact, and the successful implementation of each project depends on their balance, i.e., cost management (reasons for increased costs), time management (extending construction time), and quality and resource management (maximum use of project resources) [6]. Hence, it is necessary to devise an effective solution. In the meantime, value engineering is one of the effective tools used”to r’duce costs and improve project performance [7,8]. Due to the implementation complexities in most construction projects, value engineering is an effective method and an efficient economic technique used In cost, time, and quality management [9]. This method eliminates or modifies items that cause unnecessary costs without adversely affecting the basic functions of the plan [10]. The actual costs and time of the activities should be regularly monitored and controlled to achieve the planned goals of the project time, cost, and quality [11]. Hence, the causes of deviation from the predicted values should be identified to control management performance. Mechanisms must be applied to ensure their performance to achieve the project goals and deal with existing limitations. Regarding project objectives, including cost-effectiveness and timeliness, it is necessary to identify and evaluate the discrepancy between the anticipated and actual costs spent and the planned and actual time performed in the predefined periods. Hence, the effects of schedule variance on the whole project are clearly defined. A standard, common and efficient method used to analyze and measure the project’s technical performance is the earned value analysis, which shows the need for possible corrective measures through the analysis of the discrepancies and provision of initial indications of the project performance [12]. For example, putting large projects into operation a few months ahead of schedule will have a decisive effect on project marketing and profitability [6].

Building materials and consumables are considered non-renewable resources in construction projects, which may become more expensive if construction time is delayed. Therefore, a much higher cost than the planned cost must be spent in the construction process of the project due to the inflation rate. Thus, the increase in the inflation rate and high costs of consumption resources leads to the imposition of unforeseen losses to the project [6]. Labor resources, including staff and machinery in construction projects, are considered renewable resources in the project, the costs of which will increase if the construction time is delayed, probably leading to the lack of economic justification for the project [6]. Because engineering projects need money for investment, it is essential to correctly reflect the time value of the money spent when evaluating these projects [13]. Meanwhile, money can be earned through investment in a certain period with a specified interest rate. In other words, money should be turned into utility as soon as possible because as time passes, the amount of money is added due to the interest, which indicates that money makes money [14].

According to engineering economics knowledge, considering the time value of money factor, capital must be charged interest if the project is stopped or delayed because this capital could be spent in another place where it would be guaranteed with an interest rate as a percentage [15].

Thus, considering the initial capital of the project, provided through fundraising or a loan with an annual interest rate, an amount must be added to the initial capital as an additional interest cost for each year the completion of the project is delayed. In addition, a cost should be imposed as a loss to the project due to the time value of money, according to the minimum acceptable attractive rate. It may be assumed that as the construction project is prolonged and its completion is delayed, the final product will become more expensive, adding to the economic value of the project, although this issue does not conflict with the timely completion of the project. The mean delay time in projects is beyond average in developing countries such as Iran, increasing costs considerably. Because the cost items are latent and no cash is paid for them, they may be invisible to the managers, who may not even pay attention to such items. Thus, cost monitoring is required when project management techniques are implemented to improve project management performance [6].

Before starting the project management processes for a construction project, the economic feasibility of the project should be checked concerning the predicted costs and revenues using economic and engineering evaluation techniques such as value engineering. When the project is economically confirmed, it is recommended to plan and control the process of its implementation. Thus, any delay in the project will change the projected costs according to the above factors. Therefore, when a project is delayed, its economic justification should be re-analyzed. In such conditions, its attractive rate may be lower than the minimum acceptable attractive rate, indicating that the project is no longer economically justified [6].

According to the abovementioned, it is important to identify and examine the influential factors on the performance improvement of construction project management with the value engineering approach based on earned value analysis for the successful evaluation of project performance. Therefore, this research identified the influential factors on the improvement of construction project management with the value engineering approach based on earned value analysis. The Delphi technique was used along with a comprehensive review of the research literature to identify influential factors. The results of this research can help project beneficiaries Improve construction project management performance through earned value-based value engineering strategy.

2. Literature Review

There are many studies on project management and its performance, value engineering, and earned value, highlighting great diversity in the field of value engineering research, despite the obvious difference in the number of methodological steps and the process of solving the value problem. For example, Farati and Nazimi [16] identified and prioritized value engineering factors in road construction projects using the fuzzy Delphi technique. Based on their findings, the factors of compatibility with existing machines, information acquisition, and work experience were the most important engineering factors of the value of road construction projects. In addition, the speed of construction order completion ranked as the least important factor.

Construction is an area of study in which adequately making decisions can mean the difference between success and failure. Moreover, most of the activities belonging to this sector involve considering several conflicting aspects, which hinder their management as a whole. Multi-criteria decision-making analysis arose to model complex problems like these [17]. In another study, Karunasena [18] examined the concept of value planning and its applications, indicating more importance in using the main axes of value methodology considering risk categories and strategic planning when determining the main frameworks and image of the plan compared with other methodological approaches to value. The use of value methodology as creative and systematic teamwork contributed to the optimal use of resources, the development of human resources, and the transformation of population growth from a threat to an opportunity. Success in value engineering and reaching a suitable output requires attention to many points, along with the use of various techniques and tools, turning the value engineering process into a complex process. Thus, there are still many fields of study more than a few decades after the invention and application of value engineering and the progress made [19]. The review of research on earned value management shows that the factors presented in the earned value method are Insufficient and necessitate the design of more effective factors for project planning and control. As a result, researchers have provided new factors to complete this method by examining the factors of the earned value method [20]. For example, Lu [21] introduced a project reliability control model based on quality, cost, process, and safety criteria. In addition, Nejatiyan and Aminzade [22] introduced a model by adding factors of financial and time value, as well as the financial and time status of the project.

Moreover, other similar studies (e.g., [23,24,25]) presented models that made it possible to control the cost and time of the project using statistical analyses. Considering the increasing use of computers and the high speed of computer programs, researchers have also sought to design software to calculate the factors of the earned value method, implement the earned value method in the best way possible, or implement the earned value method in a group of projects of an organization. Some articles have also focused on how to calculate the earned value in existing project management software such as Primavera and Microsoft Project. Nejatian and Aminzadeh [22] presented a new model for the earned value management system, which was implemented in MATLAB software to calculate and report the discrepancies of time and cost compared to the predetermined plan with negligible units. Similarly, Ghanem and Abdelrazig [26] presented a computer-based program for calculating the resulting value method in construction projects. The earned value technique applies to all ongoing projects, regardless of their nature (for instance, some projects may be short-term or long-term, whereas others may have extremely high costs). As a result, some factors of the earned value method are more important for some projects. Project progress reports, which are the main basis for earned value calculations, are often presented in an approximate form, and the work progress information has an uncertain nature in most projects; however, all earned value analysis models presented so far have considered project information definitive. Besides, many value engineering studies in construction projects use verbal and imprecise judgments, necessitating the use of multi-factor decision-making methods with a fuzzy logic approach instead of the usual methods.

As basic principles in engineering economics, the time value of money (the value of money depends on time and changes over time), equivalence (the value of money decreases over time), interest and its rate (the cost of using capital), minimum attractive rate of return (investment value), and the rate of return on investment (the cost of late productivity or lost profit) should be investigated [27,28]. A project is economical if the rate of return on investment is higher than the minimum attractive rate (ROR > MARR) [29,30].

According to the above discussion, the influential components of performance management of construction projects from the viewpoint of value engineering based on earned value analysis can be divided into four main groups, including project management, value engineering, earned value management, and engineering economics.

• Management is the act of balancing between different firm activities, i.e., reducing or increasing activities, simultaneously eliminating unnecessary activities and establishing regular ones, and doing more work in new fields with fewer resources [31]. Project management is the process of planning, scheduling, and controlling project activities to achieve the time, cost, and performance (qualitative) goals of the project within the defined scope of work and the efficient and effective use of resources [32].
  Cost management is a process to ensure that the project is completed within the expected cost and includes resource planning, cost estimation, budgeting and budget allocation, cash flow, and cost management and control [33,34]. Project cost management includes the processes necessary to ensure that the project team completes the work and activities in a project within its approved budget. Project managers must ensure that their project is well-defined and has adequate time and cost estimates along with a realistic approved budget. One of the duties and skills of the project manager is to keep the project stakeholders satisfied while constantly trying to reduce and control costs. Project cost management covers processes related to planning, estimation, budgeting, financial provision, capital provision, and cost management and control, leading to project completion with approved budgeting [35].
  Time management is a process to ensure that the project is completed within the expected time frame and includes preparation of a list of activities, duration estimation, schedule preparation, and control. Project time management includes the necessary processes to complete the project on time [36]. The exact time of project completion is estimated considering the time performance index, the planned and the achieved duration as the main Input variables, and the predicted and spent time as the output variable [37].
  Scope management of the project comprises the processes necessary to ensure that the work required and only the work necessary for the successful completion of the project are included. Scope management is mainly related to determining and controlling what is included in the project [38].
• Value engineering represents a creative attitude to optimize the life cycle, save time, increase profits, improve the quality of problem-solving, and ensure optimal use of resources [39].
• Earned value results from this idea that every deliverable item of a project (value) has a planned cost that is completed and realized with that value, known as “earned value” that is produced by the project [40]. Earned value management systems (EVMS) are practical, comprehensive, and reliable management systems that combine cost, time, and technical performance, making it possible to predict project costs and planning duration by calculating cost and schedule variance. The earned value management method shows the need for potential corrective measures by providing initial indications of project performance [41].
  EVMS is “an organization’s management system for project and program management that integrates a defined set of associated work scopes, schedules, and budgets for effective planning, performance, and management control; it integrates these functions with other business systems such as accounting and human resources among others”, as defined by Aramali and colleagues [42].
  The earned value is illustrated under three main headings: project integration management, project cost management, and project time management [43]. Earned value management in its various forms is a commonly used method of performance measurement, integrating the measurements of project schedule, cost, and scope to enable the project management team to evaluate and measure the progress and performance of the project. Earned value measurement (EVM) is a project management technique that requires the formation of an integrated baseline against which performance can be measured throughout the project. The principles of EVM can be used for all projects and industries [44].
  A change proposal with a value engineering approach (change proposal) is presented by the contractor during the contract period to reduce the costs of implementation, operation, and maintenance and improve efficiency and other interests of the employer while simultaneously conducting the work with a better quality or according to the agreement. Employers will pay a part of the savings to the contractor if the change proposal is accepted [45].
• Engineering economics is a set of mathematical techniques for economic evaluation and comparison of projects. In simpler terms, engineering economics is a decision-making tool to choose the most economical project [46]. The basic concepts and main symbols in the economic evaluation of projects are explained considering the time value of money. The basic concepts include the time value of money (the value of money depends on time and changes over time), equivalence (the value of money decreases over time), interest and its rate (the cost of using capital), minimum attractive rate of return (investment value), and the rate of return on investment (the cost of late productivity or lost profit) which should be investigated. A project is economical if the rate of return on investment is higher than the minimum attractive rate (ROR > MARR) [29,30].

According to a comprehensive review of the research literature, the identified influential factors on the improvement of performance management in construction projects with a value engineering approach based on the earned value analysis are shown in

Table 1. Influential factors on construction projects performance management improvement through earned value-based value engineering strategy.

Project Management Performance			Engineering Economics
Cost Time Quality Cost Goal Time Goal Quality Goal Scope Goal		[5]	Time Value of Money Equivalence Interest The Minimum Attractive Rate of Return (MARR) Interest Rate The Rate of Return (ROR) The attractive Rate of Return (ARR)	[47,48,49,50,51,52]
Value Engineering Approach			Earned Value Management
Worth Value Use Value Esteem Value Exchange Value Cost Value Cost Main Function Secondary Function	Unnecessary Function Methodical Function Time Value Index Cost Objective The Purpose of Operation Value Goal	[9,53]	Planned Value Actual Cost Earned Value Cost Variance Percentage Cost Performance Index Schedule Variance Percentage Schedule Performance Index Schedule %Complete Performance %Complete	[33,54,55,56]

.

3. Research Methodology

The current study aims to determine the influential factors on construction projects’ performance management improvement through earned value-based value engineering strategy. It is applied in terms of objectives and mixed qualitative-quantitative research with an exploratory approach in terms of paradigm. The development stages should be identified based on collective wisdom due to the novelty of the subject and its wide dimensions. Therefore, the Delphi approach was used along with the content analysis method to achieve results close to reality in addition to effective communication with experts and achieving consensus among their opinions. The research used a combination of qualitative and quantitative methods according to the type of data and their conditions. The Delphi panel consisted of twenty experts in project management and administrators specializing in the management of construction projects utilizing a value engineering approach, as determined due to the statistical population of the study. The experts were asked to give their opinion on whether the updated identified factors could be considered influential factors in the improvement of management performance in construction projects with a value engineering approach based on earned value analysis or not. Note that the importance of all items was determined on a scale of 1–5, and only items with an importance of ≥3 were selected. This method is one of the criteria proposed by [57] for the members’ consensus on various items and their selection or exclusion in the Delphi technique. First, a detailed and comprehensive review of the research literature on factors affecting the improvement of construction project management performance was conducted, because of which 39 influential components related to the overall research were identified in 4 main dimensions, including 7 components of project management performance, 16 components of the value engineering approach, 9 components of earned value management, and 7 components of the basic principles of engineering economics. In the next step, 20 questionnaires were distributed among experts. The experts merged 7 components due to their close semantic relationship, leading to 34 important influential components. The literature of three other components was changed, and nine more components were added using expert opinions. After applying the opinions of experts, 39 important, influential components were determined, which were evaluated and investigated in the third stage using Delphi, the technique to analyze quantitative data.

3.1. Delphi Survey Technique

The Delphi approach eliminates insignificant variables while preserving the main variables and factors that have the greatest impact. The validity of the Delphi technique does not depend on the number of participants but on the scientific validity of the participating experts. In this regard, there is no consensus between traditional and fuzzy Delphi techniques [58]. There are no strict and explicit rules on the selection of experts who answer the Delphi questionnaire. However, it should be noted that the quality of experts is more important than their number [59]. Therefore, the specialists and experts who have enough knowledge and experience in a similar topic and enough time for participation, along with effective communication skills, make up the participants in the Delphi survey [60]. In terms of number, there are usually <50 and often between 10 and 20 experts involved [61]. The number of experts depends on factors such as the homogeneity of the sample, the purpose of Delphi, the range of difficulty, the quality of decision-making, the ability of the internal research team, external credibility, the time of data collection, the available resources, and the scope of the problem under study [61]. Because the research was conducted considering the current state of the Iranian construction industry, the members of the Delphi panel and respondents were selected from experts in the field of project management and managers specializing in the management of construction projects in Iran who mastered engineering and construction management principles and project financial management. Moreover, they were familiar with the PMBOK standard, concepts of value engineering, and earned value analysis. They had more than twenty years of expertise and skills in international project management. The steps of the Delphi technique of the current research were as follows:

Step 1. Identification of the research factors using a comprehensive review of the theoretical foundations of the research.

Step 2. Collection of the opinions of decision-making experts using questionnaires, distributed after identifying the group of experts and forming a decision-making group consisting of experts related to the research topic.

Step 3. Checking and screening factors by comparing the earned value of each index with the threshold value. The threshold value, which is considered 0.7, is calculated in several ways. First, the triangular fuzzy values of experts’ opinions should be calculated, followed by estimating their fuzzy average to calculate the mean of n respondents’ opinions.

Step 4. Consensus and completion of fuzzy Delphi indicate that the respondents have reached a general decision about the factors and a stage after which nothing special happens in the groups [62].

According to the results of the first round of Delphi, the experts merged seven factors because of their close semantic connection. Cost, time, and quality were merged because they make the triple constraints or the triangle of the project, contributing as the three main elements of every project. The experts believed that project management seeks to simultaneously deal with these elements at a comprehensive level. In addition, the cost, time, quality, and scope goals were merged because insufficient knowledge and the inability to clearly define the needs and expectations of the stakeholders will lead to confusion in the definition of the scope of the project. If more efforts are required to compensate for such problems, excess cost and time will be imposed on the project. Therefore, balance among these four interacting goals can ensure the successful implementation of each project. According to experts, if the scope of work is not properly defined, the success of the project will be overshadowed or limited. Based on the opinions of experts, 34 important, influential factors were identified. After receiving corrections from the experts, the questionnaire was redesigned and sent back to them.

In the second round, the experts suggested that three factors be corrected. These factors are part of the body of management knowledge in the field of project planning, and after determining the project’s scope regarding quality, the planning steps for these three factors are performed in some projects about available resources. In addition, nine new factors were proposed in this round. The cost was also merged into the project cost management because each cost management program should consider the variables that affect the project budget, including materials and people, along with fixed costs, such as economic cost in teams, to obtain the required information regarding the financial commitment to the project. Time was also merged into project schedule management because effective time management is one of the biggest challenges of project management, necessitating consideration of variables that affect project time, including materials and people, to obtain the required information regarding the time commitment to the project while also ensuring proper prioritization and management of the team needs and stakeholder expectations. Therefore, the questionnaire was sent to the experts for the third time after revision. In this round, all the experts agreed that the questions and categories given in the questionnaire were suitable.

Table 2. The third round of the Delphi questionnaire.

No	Dimensions	Identified Factors	Mean
1	Project management performance	Project planning	5.00
2		Project scheduling management	4.90
3		Project management processes	5.00
4		Project management standards	5.00
5		Project management software	4.80
6		Project cost management	5.00
7		Project scope management	4.80
8		Project resource management	5.00
9		Project stakeholder management	3.95
10	Value engineering approach	Worth	5.00
11		Value	5.00
12		Use value	4.75
13		Esteem value	4.85
14		Exchange value	4.65
15		Cost value	5.00
16		Main function	4.80
17		Secondary function	5.00
18		Unnecessary function	4.90
19		Methodical function	3.75
20		Value index	4.80
21		Cost objective	5.00
22		The purpose of operation	3.90
23		Value goal	4.85
24	Earned value management	Planned value	4.85
25		Actual cost	4.05
26		Earned value	4.85
27		Cost variance percentage	5.00
28		Cost performance index	4.95
29		Schedule variance percentage	4.85
30		Schedule performance index	4.75
31		Schedule %complete	5.00
32		Performance %complete	4.00
33	Engineering economics	Time value of money	5.00
34		Equivalence	4.05
35		Interest	3.75
36		The minimum attractive rate of return (MARR)	5.00
37		Interest rate	5.00
38		The rate of return (ROR)	4.85
39		The attractive rate of return (ARR)	5.00

reports the calculation results of this round. Kendall’s agreement coefficient based on Formula (1) was used to determine the level of consensus among the members, the results of which are reported in

Table 3. The results of Kendall’s coefficient of concordance.

Result	Sig.	Df.	Chi-Square	Kendall Coefficient of Concordance	The Number of Judges
Strong Consensus	0.000	38	541.370	0.712	20

. Kendall’s coefficient of concordance is a scale to determine the degree of coordination and agreement between several rating categories related to N objects or individuals. This scale makes it possible to find the rank correlation between K rank sets and is especially useful in inter-rater validity research. Kendall’s coefficient of concordance shows that people who have arranged several categories based on their importance have used the same criteria to judge the importance of each category and agree in this sense [63]. Kendall’s coefficient of concordance can be calculated based on Equation (1).

$$\mathrm{W}=\frac{\mathrm{S}}{\frac{1}{12}{\mathrm{k}}^2\left({\mathrm{N}}^3-\mathrm{N}\right)}$$

(1)

In which S = ∑[R_j – $\frac{\sum {\mathrm{R}}_{\mathrm{j}}}{\mathrm{N}}$]² is the sum of the squares of the deviations of R_j from the mean of R_js; R_j is the set of ranks related to a factor; K is the number of ranking sets (number of judges); N is the number of ranked factors; and $\frac{1}{12}{\mathrm{k}}^2\left({\mathrm{N}}^3-\mathrm{N}\right)$ is the maximum sum of squares of deviations from the mean of R_js (the sum of S, which is observed if there is complete agreement among K rankings).

The value of this scale ranges from 0 to 1, indicating the degree of consensus obtained through the Delphi panel (very strong W > 0.9, strong W > 0.7, moderate W = 0.5, weak W = 0.3, and very weak consensus W = 0.1). It is worth noting that the significance of the W coefficient is not enough to stop the Delphi process. Even tiny values of W are considered significant for panels with more than 10 members [63].

3.2. Survey Questionnaire Assessment

The validity of a test is its ability to measure the trait that the test is designed to measure [64]. Face validity, content validity using the Lawshe formula, and construct validity were used along with confirmatory factor analysis in SmartPLS software to verify the research questionnaire.

3.2.1. Face Validity

Face validity is about whether a test measures what it is supposed to measure. This type of validity is concerned with whether a measure seems relevant and appropriate for what it is assessing only on the surface. In this study, the face validity of the questionnaire was confirmed by several respondents.

3.2.2. Content Validity

Content validity is used to check the components of a measurement tool, representing a structural feature of the measurement tool that is integrated into it at the same time as the test is developed [65]. The content validity of a test is determined by experts in the studied subject. Because the questionnaire used in the current research was designed by the researcher based on the results of the qualitative part of the research, the content validity of Lawshe was used to check the content validity. Thus, the questionnaire was distributed among 20 experts, including university experts, managers, and senior experts, who were active in the field of performance management of construction and engineering projects to give their opinion based on a three-level scale (the item is necessary, the item is useful but not necessary, and the item is not necessary). The frequency of each expert’s agreement with each of the questions in the questionnaire was then determined, followed by the calculation of the content validity of Lawshe according to Formula (2) [66]. The obtained validity was compared with

Table 4. The minimum amount and the number of experts in content validity [67].

The Number of Experts	5	6	7	8	9	10	11	12
The minimum amount	0.99	0.99	0.99	0.85	0.78	0.62	0.59	0.56
The number of experts	13	14	15	20	25	30	35	40
The minimum amount	0.54	0.51	0.49	0.42	0.37	0.33	0.31	0.29

, which shows the minimum amount and the number of experts in content validity [67]. The results indicated that the Lawshe coefficient is higher than the minimum value for all questions in the questionnaire (0.42), indicating that the designed questionnaire had the required content validity. Note that the content validity ratio for the overall research questionnaire was 0.871.

Table 5. Reliability of each questionnaire item with the Lawshe formula.

No.	Identified Factors	Necessary	Useful but Not Necessary	Not Necessary	Lawshe’s Content Validity Ratio
1	Project planning	20	0	0	1
2	Project scheduling management	19	1	0	0.9
3	Project management processes	20	0	0	1
4	Project management standards	20	0	0	1
5	Project management software	18	2	0	0.8
6	Project cost management	20	0	0	1
7	Project scope management	18	2	0	0.8
8	Project resource management	20	0	0	1
9	Project stakeholder management	18	2	0	0.8
10	Worth	20	0	0	1
11	Value	20	0	0	1
12	Use value	16	4	0	0.6
13	Esteem value	17	3	0	0.7
14	Exchange value	16	4	0	0.6
15	Cost value	20	0	0	1
16	Main function	18	2	0	0.8
17	Secondary function	20	0	0	1
18	Unnecessary function	18	2	0	0.8
19	Methodical function	15	5	0	0.5
20	Value index	17	3	0	0.7
21	Cost objective	20	0	0	1
22	The purpose of operation	18	2	0	0.8
23	Value goal	18	2	0	0.8
24	Planned value	18	2	0	0.8
25	Actual cost	19	1	0	0.9
26	Earned value	18	2	0	0.8
27	Cost variance percentage	20	0	0	1
28	Cost performance index	19	1	0	0.9
29	Schedule variance percentage	17	3	0	0.7
30	Schedule performance index	17	3	0	0.7
31	Schedule %complete	20	0	0	1
32	Performance %complete	20	0	0	1
33	Time value of money	20	0	0	1
34	Equivalence	19	1	0	0.9
35	Interest	18	2	0	0.8
36	The minimum attractive rate of return (MARR)	20	0	0	1
37	Interest rate	20	0	0	1
38	The rate of return (ROR)	19	1	0	0.9
39	The attractive rate of return (ARR)	20	0	0	1

shows the reliability of each item in the questionnaire with the Lawshe equation.

$$\mathrm{C}\mathrm{V}\mathrm{R}=\frac{\left(n_e-\frac{N}{2}\right)}{\frac{N}{2}}$$

(2)

where CVR is the content validity ratio, n_e is the number of experts considering the desired item in the questionnaire appropriate, and N is the number of experts examining the questionnaire.

3.2.3. Construct Validity

Index reliability, convergent validity, and divergent validity are used to check the fit of the measurement models, while R², Q², F², and GOF are used to examine the final fit of the model. It should be noted that the reliability of the index is also measured by the three criteria of factor loadings, Cronbach’s alpha, and composite reliability, which are examined below.

Factor loading is a value between zero and one. If the factor loading is <0.3, the relationship is considered weak and is manually eliminated by removing the factors with a factor loading of <0.3. A factor loading between 0.3 and 0.6 is acceptable, and >0.6 is highly desirable [68]. Cronbach’s alpha coefficient is used to evaluate the reliability of the internal consistency of the model, with a value ranging from 0 to 1. To calculate composite reliability, factors with higher factor loading are more important, making the composite reliability values of the constructs more realistic and accurate than their Cronbach’s alpha. The acceptable value for Cronbach’s alpha and composite reliability is ≥0.7 [69]. Convergent validity examines the degree of correlation of each construct with the research questions. The higher the correlation, the better the fit. Fornell and Larcker [70] introduced the average variance extracted (AVE) measure to examine convergent validity and stated that an AVE value of >0.5 indicates acceptable convergent validity. R² expresses the number of changes in each of the dependent variables of the model, which is explained by the independent variables. R² is calculated only for endogenous structures of the model and is zero in the case of exogenous structures. The value of this coefficient varies from 0 to 1, and larger values are more favorable, indicating a better fit of the model. Chin [71] considered values close to 0.67 favorable, values close to 0.33 normal, and values close to 0.19 poor. Q² determines the predictive power of the model. Models that have an acceptable structural fit must be able to predict factors related to the endogenous structures of the model. In other words, if the relationships between the structures are correctly defined in a model, the structures can have a sufficient effect on the factors of each other. Henseler et al. [72] believe that the positive value of Q² indicates a favorable fit of the model and its good predictive power. F² also determines the intensity of the relationship between the constructs of the model. According to Cohen [73], the values of 0.02, 0.15, and 0.35 indicate small, medium, and large effect sizes, respectively. The GOF index is used to check the validity or quality of the model and is calculated using Formula (3). The value of this index is between 0 and 1, with values close to 1 indicating the appropriate quality of the model. Wetzels et al. [74] introduced three values, 0.1, 0.25, and 0.36, as weak, medium, and strong for GOF, respectively. As indicated in

Table 6. Fitness criteria of the research questionnaire.

Dimensions	Cronbach’s Alpha	CR	AVE	Communality	R2	Q2	F2	GOF
Earned Value Management	0.910	0.927	0.587	0.344	0.807	0.442	4.185	0.531
Engineering Economics	0.919	0.935	0.673	0.452	0.692	0.416	2.251
Project Management Performance	0.904	0.922	0.569	0.323	0.843	0.415	5.383
Value Engineering Approach	0.926	0.937	0.516	0.266	0.921	0.423	11.734

, the fit indices of the model were all confirmed. In addition, as shown in Figure 1, the factor loadings related to the identified dimensions and factors were all confirmed.

On the other hand, the degree of the relationship of a component with its factors compared to its relationship with other components is determined by divergent validity. Divergent validity is acceptable when the AVE for each component is greater than the shared variance between that component and other components (i.e., the square of the correlation coefficients between components) in the model. In structural equation modeling, this is examined through a matrix, the rows of which contain the values of the correlation coefficients between the components and the square root of the AVE values of each component. This model has acceptable divergent validity if the numbers included in the main diagonal are greater than their underlying values [70]. As seen in

Table 7. Divergent validity using Fornell and Larker values.

		1	2	3	4
1	Earned Value Management	0.766
2	Engineering Economics	0.685	0.821
3	Project Management Performance	0.763	0.659	0.754
4	Value Engineering Approach	0.707	0.734	0.678	0.719

, the validity model has an acceptable variance. Equation (3) determines the GOF index:

$$\mathrm{G}\mathrm{O}\mathrm{F}=\sqrt{\mathrm{a}\mathrm{v}\mathrm{e}\mathrm{r}\mathrm{a}\mathrm{g}\mathrm{e}\left(\mathrm{C}\mathrm{o}\mathrm{m}\mathrm{m}\mathrm{o}\mathrm{n}\mathrm{a}\mathrm{l}\mathrm{i}\mathrm{t}\mathrm{y}\right)\times \mathrm{a}\mathrm{v}\mathrm{e}\mathrm{r}\mathrm{a}\mathrm{g}\mathrm{e}\left({\mathrm{R}}^2\right)}$$

(3)

4. Presentation of Analytical Results

4.1. Data Normality Test

As the results of

Table 8. Kolmogorov–Smirnov test to check the normality of research data.

Variable	Sig.	Statistics	Error Value	Hypothesis Confirmation	Normal Distribution
Total Questionnaire	0.200	0.142	0.05	H0	Yes

H0: the data of the research variables have a normal distribution. H1: the data of the research variables do not have a normal distribution.

show, the significance value is >0.05 in the entire research questionnaire, confirming the null hypothesis at the confidence level of 95% and the normal data distribution.

4.2. To What Extent Do Influential Factors Play a Role in the Improved Management Performance of Construction Projects Utilizing the Value Engineering Approach and Earned Value Analysis?

According to

Table 9. One-sample t-test results.

Dimension	No.	Mean	SD	Test Value = 3			Upper Limit	Lower Limit
				t	Df.	p-Value
Project Management Performance	20	3.933	0.540	7.729	19	0.000	1.186	0.680
Value Engineering Approach	20	3.550	0.419	5.869	19	0.000	0.746	0.353
Earned Value Management	20	3.383	0.465	3.686	19	0.002	0.601	0.165
Engineering Economics	20	4.221	0.476	11.475	19	0.000	1.444	0.998
Total	20	3.720	0.352	9.140	19	0.000	0.885	0.555

, the total mean of the questionnaire is 3.720, and the average dimensions of the questionnaire are 3.933, 3.550, 3.383, and 4.221 for project management performance, value engineering approach, earned value management, and engineering economics, respectively. Given the p-value of <0.05, the influential factors on the improvement of management performance in the mentioned dimensions and in all the items of the questionnaire had a significant difference with the value of the test (3), above average. On the other hand, considering the positive upper and lower limits of the confidence interval, it can be concluded that all the items and dimensions had a relatively strong role in improving management performance in construction projects with the value engineering approach based on earned value analysis.

4.3. What Is the Importance of Influential Factors on Management Performance Improvement in Construction Projects with a Value Engineering Approach Based on Earned Value Analysis?

According to

Table 10. Friedman test results (significance of identified dimensions and factors).

Scale	Chi-Square	Df.	Sig.	Test Result
Dimensions	30.660	3	0.000	H0 rejected
Identified factors	168.464	38	0.000	H0 rejected

H0: the mean ranks of dimensions and factors are equal. H1: the mean ranks of dimensions and factors are not equal.

, the level of significance is less than the threshold of 0.05 (p < 0.05), revealing a significant difference between the dimension ranking and the identified factors on the improvement of management performance in construction projects with a value engineering approach based on an earned value analysis.

The importance and ranking of the factors were determined using the Delphi approach after the opinions of the sample members were examined and evaluated, and the influential factors on the improvement of performance management in construction projects through earned value-based value engineering strategy were discovered. Based on Friedman test results shown in

Table 11. Friedman test results for the mean rank of the identified dimensions and factors.

No.	Dimension (Rank)	Identified Factors	Mean Factors Rank	Factors Rank within Group	Total Factors Rank
1	Project Management Performance (2)	Project Planning	23.40	4	11
2		Project Management Processes	21.83	7	15
3		Project Management Standards	21.73	8	16
4		Project Management Software	6.33	9	39
5		Project Cost Management	21.98	6	13
6		Project Schedule Management	22.33	5	12
7		Project Scope Management	27.40	3	3
8		Project Resource Management	28.63	2	2
9		Project Stakeholder Management	29.48	1	1
10	Value Engineering Approach (3)	Worth	21.43	1	17
11		Value	20.35	2	18
12		Use Value	20.20	3	19
13		Esteem Value	20.10	4	20
14		Exchange Value	20.00	5	21
15		Cost Value	19.45	6	22
16		Main Function	19.18	7	23
17		Secondary Function	18.93	8	24
18		Unnecessary Function	18.53	9	25
19		Methodical Function	17.68	10	26
20		Value Index	17.65	11	27
21		Cost Objective	14.40	12	35
22		The purpose of Operation	13.48	13	36
23		Value Goal	12.20	14	37
24	Earned Value Management (4)	Planned Value	21.85	1	14
25		Actual Cost	17.05	2	28
26		Earned Value	10.43	9	38
27		Cost Variance Percentage	16.78	3	29
28		Cost Performance Index	16.75	4	30
29		Schedule Variance Percentage	16.65	5	31
30		Schedule Performance Index	16.00	6	32
31		Schedule %Complete	15.73	7	33
32		Performance %Complete	15.40	8	34
33	Engineering Economics (1)	Time Value of Money	26.23	1	4
34		Equivalence	26.20	2	5
35		Interest	25.88	3	6
36		The minimum Attractive Rate of Return (MAR)	25.13	5	8
37		Interest Rate	25.45	4	7
38		The rate of Return (ROR)	23.93	7	10
39		The attractive Rate of Return (ARR)	23.95	6	9

, the dimension of engineering economics ranks first with a mean of 3.50, followed by project management performance (3.00), the value engineering approach (2.05), and earned value management (1.45) at the second-to-fourth ranks. In addition, the Friedman test resulted in the following factors ranking from the first to the 39th: stakeholder management (29.48), project resource management (28.63), project scope management (27.40), time value of money (26.23), balance (26.20), interest (25.88), interest rate (25.45), minimum investment rate (25.13), attractive rate (23.95), investment return rate (23.93), project planning (23.40), project schedule management (22.33), project cost management (21.98), planned value (21.85), project management processes (21.83), project management standards (21.73), worth (21.43), use value (20.20), esteem value (20.10), exchange value (20.00), cost value (19.45), main function (19.18), secondary function (18.93), unnecessary function (18.53), methodical function (17.68), value index (17.65), actual cost (17.05), cost variance (16.78), cost performance (16.75), schedule variance (16.65), program performance (16.00), schedule performance (15.73), performance %Complete (15.40), cost objective (14.40), purpose of operation (13.48), value goal (12.20), earned value (10.43), and project management software (6.33).

5. Discussions of Analytical Results

Any activity’s performance evaluation is not solely centered on the outcome of its steps. Before beginning the work, during the design, construction, and execution phases, as well as at the end of the project (operation), it is essential to measure and evaluate performance. Construction projects are not exempt from evaluation by the steps. Considering various project management standards, including the PMBOK guide, numerous knowledge areas for successful project management have been provided, each of which is crucial and significant for the project’s success. To evaluate or measure the performance of construction projects, we need a model that evaluates and measures each of these fields of knowledge not only separately but also in an integrated manner and across multiple projects. To set measuring and controlling the performance of project management is one aspect of determining the project’s success.

The costs and time for the actual activities must be monitored and controlled regularly to keep the project economical and use the budgeted cost of work scheduled efficiently as well as complete the project on time of work scheduled. In addition, to improve the situation, the causes of deviations from the predicted values must be identified, and management performance must be monitored and controlled. Certain project management mechanisms must be implemented to accomplish the project’s objectives. Regarding the project’s objectives, which include being inexpensive and on time, the variance between the anticipated cost and the actual cost of work performed, as well as the planned time and the actual time of work performed, should be evaluated so that its full impact on the project can be determined.

It is necessary to use an effective method and technique to evaluate, measure, and control the management performance of construction projects to save execution time and construction costs, maintain quality, and ultimately lower other costs. In this study, multiple connections between distinct domains are introduced. In addition, indicators for each area are measured. By combining the approaches of value engineering and earned value management, the performance measurement of project management has been evaluated in an integrated manner and in accordance with the existing relationships between various areas. By producing a clear picture of the project’s performance status, it is possible to evaluate the effectiveness of the value engineering approach in reducing cost and time, as well as its impact on the quality of management performance, and by comparing the initial planed to the actual plan. The performance of the achievement management and the project conditions are investigated so that it is possible to simultaneously measure, evaluate, and control their performance.

The results of the study revealed that engineering economics has the highest importance among the four groups. Because engineering projects need money for investment, the correct reflection of the time value of the money used is crucial in the evaluation of these projects, as money can be earned through investment in a certain period with a certain interest rate. In other words, it is recommended to convert our money into utility as soon as possible because the presence of interest adds to the amount of money as time passes. According to the time value of money, if the project is stopped or delayed, interest costs will be added to the capital because this capital could be spent elsewhere with guaranteed profitability and an interest rate in the form of a percentage. Therefore, considering the initial capital of the project, provided through capital attraction or a loan with an annual interest rate, an amount must be added to the initial capital as an additional interest cost for each year that the completion of the project is delayed.

In addition, a cost should be imposed as a loss to the project based on the minimum acceptable attractive rate, which is attributed to the time value of money. It may be assumed that as the construction project is prolonged and its completion is delayed, the final product will become more expensive, adding to the economic value of the project, although this issue does not conflict with the timely completion of the project. The mean delay time in projects is beyond average in developing countries such as Iran, increasing costs considerably. Because the cost items are latent and no cash is paid for them, they may be invisible to the managers, who may not even pay attention to such items. Thus, cost monitoring is required when project management techniques are implemented to improve project management performance.

Based on the results, project performance management is also important after engineering economics. The lack of innovation in mathematical models developed in the field of project planning and scheduling has made it necessary to change existing models. Project management processes and knowledge levels interact with each other. In general, stakeholders determine project limits, and the project, time, cost, and quality scopes interact with each other and limit every project. The management of these limits and the balance between them significantly contribute to the successful management of project performance. Successful implementation of projects relies on the balance between project management processes and project scope management. Because time, cost, and quality are the main criteria of any project, managers always seek to complete projects in the shortest possible time, with the lowest cost and with the highest quality, to achieve success in projects.

Given the complexity of project implementation, quality has become crucial in addition to the two factors of time and cost. Hence, one of the main goals of project managers is to increase the quality of project implementation while reducing its time and costs. One of the main challenges in this regard is selecting a suitable approach to achieve the aforementioned goals. Project planning and scheduling are performed with limited resources to minimize the duration of the project. Different stakeholders have various expectations of the project. Projects often have planned and scheduled activities based on priorities and constraints to minimize construction time. In project planning, the three constraints of cost, time, and quality depend on resources, and it is possible to meet the needs of stakeholders by identifying and establishing mutual communication between them, prioritizing their expectations, and devising a project planning strategy. Construction projects include numerous and diverse activities and elements of executive operations. If project management standards are used to analyze and measure technical performance, along with modeling and simultaneous consideration of theoretical issues in line with the scope of construction projects, the management of the project scope and limitations can be integrated to find feasible solutions with minimum cost and time but acceptable quality.

According to the results, the value engineering approach had the third importance. Data entry, information production, and evolutionary circulation will lead to effectiveness, efficiency, and synergy to realize the main functions of the project, reduce cost and execution time, improve quality, and, most importantly, remove obstacles and reveal ambiguous issues in different stages of the project. Managers require a combination of standard methods and their comprehensiveness in terms of the use of the proposed knowledge and solutions to choose the right approach in decision-making in the field of project management knowledge. Therefore, the change from the traditional to the new attitudes of project management is evident. The separation of project management processes from standard methods may not only cause problems and impose high costs during the life of projects but also lead to major misunderstandings in the use of these methods.

Although the success of value engineering activities requires teamwork, the separation of these activities from project management processes can strengthen the aforementioned obstacles and make value engineering difficult. An approach that can create a logical interaction between the processes of project management and value engineering is achieved in the cycle of the project life, necessitating novel approaches in project management. This attitude deals with many problems related to the implementation of value engineering in the life cycle of the project, the relationship between the implementation methods of projects, the application of value engineering, project management, and attention to the role and position of the stakeholders, especially the beneficiaries and financiers of the project, in project management and value engineering processes. It is more appropriate to use value engineering to provide cost optimization solutions and financial control in the feasibility stages of the program and related applications in the design stage.

It is necessary to identify areas with high potential for savings and direct value engineering research toward these areas. Various elements and factors, such as government, employer, designer, consultant, contractor, and operators, are associated with the factors affecting the increase in costs and the subsequent decrease in their value depending on the type of project. The needs, expectations, and policies of the employer, standards, and the design style of the consultant impose the greatest impact on costs during the project’s lifetime. Other factors, such as the contractor or operation factors, do not have much impact on the project life cycle. In line with the abovementioned changes, it is important to use an efficient method and technique to evaluate and control construction project management performance. Such techniques help to save the cost of construction and implementation time while eliminating and reducing unnecessary costs that do not affect the scope, function, quality, beauty, and other important features of the projects. These costs are invisible and ignored in the initial reviews and stages of planning and design, although they account for a large percentage of the costs.

The last group was related to earned value management. Project performance should be regularly monitored and measured to identify schedule variance. There is always a difference between what was budgeted and what will be expended on the project. The costs and time of the actual activities should be regularly monitored and controlled, and the causes of the predicted value variance should be identified to keep the project economical and use the allocated budget efficiently. The project performance management needs regular monitoring to improve the project status. Special mechanisms must be applied to ensure their performance to achieve the goals and deal with the existing limitations of the project. Regarding the project objectives, including cost-effectiveness and promptness, the discrepancy between the anticipated and actual costs, as well as the planned and actual time in the predefined periods, should be identified and evaluated to discover its effect on the whole project.

The use of various techniques and tools is necessary for the proper control of projects and management of scope, time, and especially the cost of the project, which can be carried out through several methods, including earned value analysis as one of the most important and widely used methods. Earned value analysis is a standard, efficient, and common method used in the analysis and measurement of the technical performance of the project, highlighting the need for possible corrective measures through the analysis of variances and providing initial indications of the project performance. This method provides project managers and organizations with warning signs to take prompt action against poor project performance and increases the chances of successful project completion [22]. A comparison of the initial and actual project plan provides a clear picture of its status and a clearer evaluation of the management’s performance and the project progress, especially in construction projects. Identifying the problems and obstacles provides the chance to take the necessary measures and deal with them. In addition, the feasibility of the project can be evaluated in a costly real environment, making it possible to increase productivity during the project life.

The authors believe that in the case of the experts’ participation from different countries, the results will not undergo much change. Because this study is based on the PMBOK standard for measuring performance in all the mentioned areas, which is the common language for communication around the world as a global standard, it should be noted that the sections and knowledge areas considered in this study are based on the seventh edition of the PMBOK standard and that the next edition may necessitate changes from this perspective. One of the most significant distinctions between the sixth and seventh editions of PMBOK is the emphasis on value. The seventh edition seeks an answer to the query, “Why do we undertake this project?” Before contemplating the project management processes, it is necessary to determine the value we intend to create through the project. The seventh edition of the PMBOK emphasizes that the objective of project implementation should not be to complete the project by any means but rather to create value without sacrificing time, money, etc.

6. Conclusions and Implications of the Study

This research evaluated the influential factors on construction project management performance through earned value-based value engineering strategy. The Delphi approach was used with 20 experts in project management and managers specializing in construction project management in Iran to identify the influential factors and achieve the research objectives. First, a detailed and comprehensive study of the research literature was conducted to identify the influential factors on construction project management performance. Then, three rounds of the Delphi technique were conducted to obtain experts’ opinions on the factors identified based on the research literature and to identify and extract key influential factors on management performance in construction projects.

The findings showed that the dimension of engineering economics ranked first with a mean of 3.50, followed by project management performance (3.00), the value engineering approach (2.05), and earned value management (1.45) at the second-to-fourth ranks. The research results included the identification and ranking of the main influential factors on the management performance improvement of construction projects through earned value-based value engineering strategy, finally leading to 39 influential factors. Theoretically, factors affecting management performance improvement in construction projects with a value engineering approach based on earned value analysis form a completely new and emerging concept. In particular, the literature review confirms insufficient investigation of influential factors on the improvement of management performance in construction projects with the value engineering approach based on the analysis of earned value. The current research had some limitations, including the use of experts according to the purpose and type of research, leading to a limited number of samples. Thus, sampling limitations were the most important limitation of this study. The following suggestions are made for future research:

• Management performance modeling of construction projects with a value engineering approach based on earned value analysis in the form of a mathematical and computer conceptual model;
• Conceptual-mathematical modeling to prioritize the three project constraints and choose an approach appropriate to the project constraints considering each of the project phases, including the design or the construction and execution phase, aimed at improving management performance and the efficiency of value engineering from the perspective of project management in construction projects;
• Conceptual-mathematical modeling of the value engineering approach in construction projects by designing and proposing new value factors during a new process called “suggesting changes with the value engineering approach” to simultaneously evaluate them from different aspects, including cost, time, quality, and scope of the project;
• Conceptual-mathematical modeling of cost–time balance in the change proposal approach by designing and proposing new value factors during a new process called “change value balance” to simultaneously describe decision-making in management performance in construction projects with a value engineering approach for simultaneous identification and elimination of the project implementation obstacles and limitations;
• Conceptual-mathematical modeling of a combination of the value engineering approach and earned value management in construction projects by designing and presenting new value factors during a new process called “suggesting change with the value engineering approach based on earned value analysis” to make necessary decisions and carry out corrective measures, in line with the maximum and proper use of the project available resources and the proper projects functioning to increase productivity;
• Providing a correct reflection of the time value of money, the interest rate, the rate of return on investment, and the minimum attractive rate in modeling construction project management performance through earned value-based value engineering strategy enable accurate economic evaluation of projects.