3. Use of the PERT Method in Construction Planning and Scheduling
Today, the construction industry faces significant challenges due to projects’ increasing complexity and dynamism, including resource procurement, cost overruns, conflicts, and disputes. The involvement of a wide range of stakeholders in large-scale projects inevitably causes conflicts [
69].
3.1. Project Planning
Effective decision-making in planning seeks to obtain future results based on various desired activities. The planner finds the best options through an integrated decision analysis [
70]. Planning an engineering project involves decisions related to manpower, simultaneity of progress, sequence of activities, deadlines, subcontracting, and facility layout. These decisions are defined as project planning.
The current difficulty in controlling work has led to the adoption of more effective scheduling techniques to improve resource allocation and project management. Being efficient implies using a given budget within the necessary time. Planning is a set of decisions to achieve a final product on a desired date, considering the current situation and the internal and external factors that may affect the fulfillment of these achievements [
71].
3.2. Scheduling in Construction
According to Alias et al. [
72], the successful performance of a project depends on proper organization, scheduling, and control. The project schedule results from project planning and describes all the tasks necessary to complete the project within the planned timeframe, including durations, start and end times for each activity, and the resources and costs assigned. In project scheduling, the critical path is the set of activities that determines the project execution time. A delay in an activity on the critical path will delay the project timeframe, so these activities must receive special attention [
73].
Construction planning and scheduling are essential in any construction process since, without proper scheduling, it is impossible to make precise budgets or exact control of the activities. Scheduling must include exhaustive control of costs and deadlines and manage resources efficiently [
74]. Several scheduling methods are found in construction, such as the Gantt Chart, the CPM (Critical Path Method), the Fondhal-LPU method (Linear Point Union), and the PERT method (Program Evaluation and Review Technique). These methods are used to control the timing and sequence of activities in a project [
75].
In this sense, technological advances have significantly improved the teaching of construction scheduling, making computer knowledge necessary to reduce time in data interpretation and variable control [
76]. Scheduling methods are generally based on network systems that allow planning and controlling projects [
77]. However, construction scheduling is only the beginning of the construction process; the biggest challenge is to control the schedule by constantly updating the information to make the best decisions and use resources efficiently [
78], where the use of Game Theory for teaching a scheduling method such as PERT can bring multiple benefits.
3.3. PERT Method (Program Evaluation and Review Technique)
For non-repetitive activities, the PERT method assumes that the time required is not known in advance, including probabilities in the time analysis and the concept of expected value to obtain the project’s total duration [
79]. This method represents the logical sequence and the interrelation of all project activities through a network flow chart, with initiation nodes and branches representing different tasks, which can be successive, simultaneous, or convergent. The PERT method uses probabilistic estimates of the durations of each activity, known as optimistic, pessimistic, and most probable. In this way, it is possible to calculate the probability of completing the project within a given time frame and find a critical path [
80].
Like tools such as the Gantt chart and the CPM Critical Path, PERT helps get closer to the desired optimal point in projects [
81]. From an administrative perspective and the benefit provided to the decision-maker, PERT specifies and details how planning should be done. Among its advantages, the following stand out: Reduction of time and costs (it helps achieve the objective or complete a project with the minimum expenditure of time and cost) and optimization of resources (it minimizes the costs associated with the project and, in this way, achieves a more significant final utility and attractive returns) [
79].
In organizing project activities in an orderly and prioritized manner, tools and methods emerge that simplify planning. The PERT method (Program Evaluation and Review Technique) helps with scheduling control. It allows identifying which activities determine the duration of a project and which ones need to be controlled more to try to shorten their duration.
The PERT method is a set of methods and techniques for effectively scheduling goal-oriented activities, establishing a baseline for scheduling, evaluating costs, controlling, and re-scheduling. It consists of arranging different activities in a network, which, due to their dependencies and links, contribute to the result of the project [
82].
In developing a project, there is often uncertainty about the timing of critical activities. These, being random variables, can be associated with a probability distribution. The PERT method takes this uncertainty into account, assuming that the estimated time for each activity is based on three different values: optimistic time (To) or the minimum period that elapses when the activity occurs in an ideal manner; pessimistic time (Tp) or the maximum period that elapses when probable but infrequent risks cause long delays; most probable time (Tm) or the most frequent duration, and finally, expected time (Te) or the expected time for an activity.
The most likely estimate Tm does not have to coincide with the midpoint of (To + Tp)/2 because the duration of each activity is assumed to follow a Beta probability distribution.
The standard deviation is represented by Equation (1), and the time variance will be represented by Equation (2):
The midpoint weighs half of the most probable point
Tm; that is, the expected value
Te is the average of
and
, as can be seen in Equation (3) and is developed in Equation (4):
It can also be assumed that the project’s expected duration is a random variable approximating the Gaussian distribution, and probabilities can be calculated using a normal distribution table.
On the other hand, Equation (5) represents the probability that the project is carried out in the desired duration (
D):
where
3.3.1. Elements of the PERT Diagram
Like CPM (Critical Path Method), the PERT method allows for graphically drawing the diagram of the relationships between each activity and their interdependencies [
81]. It consists of the following elements: (a) Arrows: These are used to represent an activity to be executed. The start of the arrow represents the beginning of the activity and is associated with the node, while the arrowhead at the end of it represents the direction, from right to left; (b) Nodes: An event or milestone that has no duration, where node i is the start of one or more activities, and node j is the end of an activity. The diagram can only have one start node and one end node. Activities are linked in the nodes; (c) Dummy Activities: Represented by an arrow with a dotted line, they indicate the dependencies between activities. These do not have a duration; (d) Float: The length of time that an activity can be delayed without causing a delay in the completion of the project.
The PERT method, like CPM, was designed to provide valuable information for project managers and decision-makers. If the critical path is delayed in both tools, the same amount delays the project, and the float is the same in both cases.
3.3.2. Simple PERT Example Using Game Theory
The elaboration of a PERT diagram will be based on the data shown in
Table 2, where the times are measured in days.
Activities A, C, and E in
Table 2 will be solved using the PERT method with known times, and Equation (4) will be used to find the expected time for each activity. However, activities B and D in
Table 2 will be solved using Game Theory applied to the PERT method. For Activity B (debris removal), the following extensive game will be played, as shown in
Figure 1: the best combination of equipment must be found to perform the work at the lowest cost and in the shortest time.
Using the pairs of numbers , where “X” represents the cost of the activity and “Y” represents the time in days, the best option, also called the equilibrium of the game in (6, 3.5), can be found. The expected time is 3.5 days, the optimal time is 2 days because it is the lowest “Y”, the pessimistic time is 7 days—the longest time that the activity can take—and the average time is 3 days.
As in the previous activity, for activity
(soil improvement), different options in the game in matrix form are found, where the optimum between cost and time is found in the pair of numbers (5, 6).
Table 3 is filled in with the times obtained using both methods, and the PERT network is then constructed.
Thus,
Table 4 shows the precedence matrix with the final estimated times, and
Figure 2 shows the final network with the times calculated using Game Theory.
Given this data, the process’s duration can be determined, as shown in
Figure 2. For this specific example, the critical path will be A-B-D-E, indicating that the process will take at least 18 days.
5. Analysis of Results
The results of the assessments were processed statistically, where their central tendency and dispersion measures represented the numerical variables. In contrast, the categorical variables were represented by the frequency and percentage of each of their classes. To determine if there were changes in the test results, both by dimension and by the total results, the t-Student test was applied for paired samples, and the Wilcoxon test was applied in cases where normality was not proved through the Shapiro–Wilk test. To determine if the proportion of correct answers increased in the second assessment, the McNemar test was applied since the same subjects took the test on the second occasion. A significance level of 0.05 was used; therefore, each time the p-value associated with a test was less than or equal to 0.05, it was considered statistically significant.
5.1. Qualitative Analysis
As previously mentioned, this research’s qualitative analysis was conducted to understand the students’ perceptions of the experience, the applied methodology, and the professor’s performance. To mitigate potential biases, anonymity was ensured in the feedback collection process, and a diverse set of open-ended and scaled questions was employed. This approach reduced the likelihood of socially desirable responses and gave more authentic insights into the methodology’s practicality and effectiveness.
The study used a 19-question questionnaire, with 33 individuals asked to rate each question with a score from 1 to 7. Then, they had to answer three open questions related to the presentation of the content, the advantages and disadvantages of the method, and its application in scheduling construction projects. These questions measured the students’ perceptions and strengthened the quantitative analysis carried out in a complementary way.
The results obtained for each question are presented in
Table 5. The information indicates that no individual rated questions with a score lower than 4 (the minimum threshold considered). Furthermore, the average for each question was higher than 6.24 out of 7, obtained by question 1 (I found the class interesting). In contrast, question 17 (The practical exercises were an excellent complement to the theory) received the highest average score within the questionnaire (6.73).
The open questions contained in the qualitative questionnaire (applied after the last assessment) were as follows (along with a summary of the students’ answers per question):
The students expressed clarity regarding the content transmitted, the professor’s mastery of the subject, and the appropriate and rapid understanding of the method implemented. The majority of the opinions reflected a positive evaluation by the students regarding the class presentation, the practical lectures being well received, and having internalized the content in a more didactic way. Most of the opinions agreed that the proposed teaching method (Game Theory), due to its novelty and easy understanding, was crucial for achieving a greater understanding of the PERT scheduling method.
According to the responses given by the students, the Game Theory tool was consistent with the bibliographic review carried out for the development of this research. They also believed that Game Theory was a mathematical tool with great potential for decision-making involving time and costs. The advantages most repeated in the students’ responses were that Game Theory helped to better understand decision-making, the simplicity of the method, and the clarity of its use. The disadvantages stated were that decisions in a real-world environment, with more decision variables involved, could make the method more difficult to use.
At this point, the responses were unanimous, as the entire universe surveyed leaned towards the idea that the equilibrium studied in Game Theory and its application to the PERT method helped make decisions in the scheduling of construction projects. The students also complemented their responses by indicating that the technique learned was a helpful tool for resolving conflicts when making decisions and better understanding the relationship between costs and benefits.
In summary, the students highlighted three primary attributes of the methodology: (1) its ability to improve strategic decision-making skills, (2) the enhanced comprehension of scheduling concepts through practical application, and (3) its effectiveness in simulating real-world scenarios, which students found highly relevant to their professional development.
5.2. Quantitative Analysis
5.2.1. Preliminary Analysis
To conduct the quantitative analysis, 26 closed questions focused on the PERT method for construction scheduling were asked of the students in a pre- and post-test. To classify the areas of knowledge to be assessed, the 26 questions were grouped into four categories, each fundamental for understanding the PERT method. The first category, “Identification of activities”, grouped 6 questions and sought to measure the students’ ability to identify activities in a construction project. The second category, “Duration of activities”, also included 6 questions to assess the student’s ability to determine the duration of activities in a construction project. The third category, called “Critical Path”, included 7 questions, and its objective was to assess whether the students could determine the critical path of a project. Finally, the fourth category, “Variability and Decision”, which also consisted of 7 questions, sought to measure students’ understanding of the concepts associated with variability (typical of the PERT method) and decision-making (typical of Game Theory).
From the results obtained and shown in
Table 6, it is possible to notice that the correct answers by the students in the post-test were percentage-wise higher than the correct answers obtained by the students in the pre-test in each category. However, to evaluate whether these differences were statistically significant, it was necessary to perform other statistical tests, so the normality of the data was previously verified. To do so,
Table 6 shows the results of the Shapiro–Wilk Normality test, where the “Critical Path” and “Variability and Decision” dimensions, together with the total number of responses, were normally distributed (
p > 0.05), in which case the t-Student test for paired samples was applied. The other dimensions, not passing the normality test, were analyzed using the Wilcoxon test.
Table 6 shows that all categories had a percentage difference greater than 8% in favor of the post-assessment, where category I “Identification of activities” had the minor difference (8.1%), while category IV had the most significant percentage difference between the pre- and post-assessment (20.8%). The minor difference in category I could be explained because “Identification of activities” is a task that is transversal to any project scheduling method, so it is unnecessary to have used Game Theory to improve. It was different for the category “Variability and Decision”, which, with a difference of more than 20% improvement between the pre- and post-test results, showed that those subjects more closely linked to probabilistic methods (such as PERT) could benefit more from topics associated with decision-making, which was widely addressed through Game Theory during the class. Overall, the total difference was more significant than 15% between the pre- and post-test at the end of the learning process of the PERT method using Game Theory.
5.2.2. Quantitative Analysis Using the Wilcoxon Test and t-Student Test
Figure 3 shows the averages of correctly answered responses for each category. In all categories, a higher percentage of correct responses was obtained in the post-test, confirmed in the analyses below.
Table 7 shows the results of the t-Student test for paired samples for the dimensions “Critical Path” and “Variability and Decision” and for the total results, where statistically significant differences were found (
p < 0.05) in favor of the post-test group. For the dimensions “Identification of Activities” and “Duration of Activities”, the Wilcoxon test was performed, where statistically significant differences were also found in both dimensions (
p < 0.05) in favor of the post-test group.
In other words, the analysis by categories obtained statistically significant differences in the results for each category. According to the above results, the methodology proposed significantly changed the students’ post-test scores for the total number of responses and each category. This finding shows the benefits of using Game Theory to teach the PERT method.
5.2.3. Quantitative Analysis Using the McNemar Test
The analysis was performed question-by-question using the McNemar test to determine if the proportion of individuals who answered the questions correctly was similar before and after implementing Game Theory as a didactical technique for teaching the PERT method for scheduling projects. Analyzing the percentage differences in each question, it was observed that in 20 of 26 questions, there were proportional differences in favor of the post-test. Additionally, in 2 of the 6 remaining questions, the same number of students answered correctly.
Table 8 shows only those questions with statistically significant differences (
p < 0.05). It should be noted that these questions had percentage variations in favor of the intervention group (post-test); that is, they achieved better performance after being taught Game Theory to learn the PERT scheduling technique, with question 7 having the lowest variation (18%) and question 8 reaching a higher percentage variation (55%).
Figure 4 shows a portion of those students who faced the pre- and post-test and improved their performance, reaching a difference between the percentages of correct questions of 55%. On the other hand, when comparing the total average scores for the 26 questions of the pre- and post-test groups, a percentage difference of 4.1% is evident in favor of the post-assessment, where in the pre-test, the students answered correctly, on average, 16.6 questions, and in the post-test, 20.7.
5.3. Discussion of Results
The main findings from the qualitative and quantitative analyses carried out in this research are summarized below.
From a qualitative point of view, the evaluation to assess the students’ perceptions of the experience showed that they highlighted the clarity of the content taught, the professor’s preparation, and the rapid understanding of the subjects covered. They also mentioned that Game Theory was a powerful tool for decision-making, highlighting its ease of use. However, they considered that its application to more complex problems present in real-world contexts could make its application difficult. Finally, when asked about the use of Game Theory to learn a scheduling method such as PERT, the answers were unanimous in that it was a handy teaching tool, significantly improving their understanding of decision-making, a cornerstone of Game Theory, but also very valuable to address the problem of uncertainty and variability present in construction projects and which PERT addresses.
Based on the quantitative analysis performed, the results obtained showed that in the four categories evaluated (“Identification of Activities”, “Duration of Activities”, “Critical Path”, and “Variability and Decision”), there were statistically significant differences between the pre- and post-test, confirming an evolution in the understanding of the contents after having used Game Theory to learn PERT. An interesting result is that although the differences between the pre- and post-test were significant in all categories, the smallest difference was in “Identification of Activities”, which could be related to the fact that this skill is required by students in any other scheduling method (i.e., not only in the PERT method). As such, students acquire it previously in the same Construction Planning and Scheduling course and related courses in their study plan by studying other scheduling techniques, such as Gantt Chart, CPM (Critical Path Method), and others. On the other hand, the most significant differences in the results were found in the “Variability and Decision” category, which corresponded precisely to all those questions where Game Theory and PERT play a much more critical role. Similarly, the detailed question-by-question analysis corroborated this finding, where the questions that showed the most significant differences were also those related to the “Variability and Decision” category.
5.4. Implications for Educators
This research introduces new insights from a methodological perspective by providing a practical approach that applies Game Theory to teach a scheduling technique commonly used in engineering (PERT or Program Evaluation and Review Technique). Even though the research specifically focuses on civil engineering students, professors from other disciplines can modify the methodology presented here for their subjects. For instance, instead of using Game Theory to teach PERT, they might teach other scheduling techniques, such as CPM (Critical Path Method), Gantt charts, or Lines of Balance. The methodology can also be applied to various engineering courses involving decision-making (e.g., Structural Analysis, Computer Simulation, among many others). In other words, educators can retain the didactical tool of Game Theory while adapting the specific engineering topic to be taught, with special emphasis on those courses where decision-making plays a critical role.
Regarding practical contributions, this study may serve as a valuable resource for engineering professors by (a) providing an introductory understanding of Game Theory and the elements of scheduling courses (e.g., PERT, CPM, Gantt, etc.) necessary for implementing challenging teaching methods that engage students; (b) facilitating the blending of Game Theory with PERT (or other courses where decision-making plays a role) in engineering education; and (c) including minor adjustments to the proposed methodology to accommodate students from different engineering disciplines or academic settings.
In terms of how to scale the proposed approach for larger class sizes, some authors have raised recommendations. To scale a way of teaching without significantly increasing the course-related resources, Petrovic and Pale [
99] suggest incorporating (a) an audience response system to make more effortless interactivity during live lectures and (b) peer review for the scalability of evaluations and to relieve professor workloads. Similarly, to improve the scalability of engineering courses, Schefer-Wenzl and Miladinovic [
100] propose reducing the load on the main lectures by outsourcing much of the non-scalable tasks to teaching assistants. In this sense, all these recommendations may be incorporated into the present study if the proposed methodology is scaled to larger class sizes.
In the end, this study offers a methodology to complement other teaching techniques, particularly for engineering courses requiring students to face decision-making processes. Utilizing Game Theory to teach a scheduling method like PERT may lead to a more engaging teaching environment compared to traditional engineering teaching techniques, ultimately enhancing academic performance by offering a teaching tool that manages engineering problems related to decision-making.
6. Conclusions
In the context of the Construction Planning and Scheduling course, part of the civil engineering academic program, the present research showed that Game Theory proved to be an appropriate didactical tool for teaching the PERT project scheduling technique. This methodology was explicitly applied to a group of civil engineering students, whose effectiveness was evaluated through pre- and post-written tests composed of closed questions that were statistically analyzed. The results revealed significant improvements in the understanding and analysis of the project scheduling concepts and the main components and use of the PERT method.
The application of Game Theory not only improved students’ understanding of the PERT method but also allowed them to obtain higher scores in subsequent assessments. Such progress was evidenced through multiple statistical analyses, highlighting an increase in the students’ ability to apply these concepts practically when supported by graphical and decision-making tools, both characteristics of Game Theory.
Additionally, the study emphasizes that Game Theory offers a challenging pedagogical approach that may help bridge the gap between theoretical knowledge and practical application. The potential to enhance decision-making skills, critical thinking, and student engagement positions it as an innovative tool in engineering education. This research sets the foundation for how Game Theory may contribute to reshaping learning outcomes across engineering disciplines.
Thus, the findings underscore the potential of Game Theory to transform traditional engineering education by promoting active learning environments. It facilitates the development of critical skills such as problem-solving and strategic decision-making, which are essential in professional practice.
On the other hand, this research offers a replicable framework for widely integrating Game Theory into engineering education. Educators may adopt this methodology to enhance their academic engineering program by emphasizing interactive and strategic decision-making problems. Moreover, this framework is adaptable to other engineering aspects, including resource management and risk analysis, enabling broader application across disciplines. Consequently, educators can further enhance their students’ engagement and learning outcomes by incorporating advanced gamified tools based on decision-making approaches.
Regarding limitations, although evaluating the same group before and after the intervention may not provide a direct comparison with traditional teaching methods, the present study has shown that implementing Game Theory is a dynamic and challenging teaching tool that could be extended to other areas beyond a single academic context (i.e., beyond the civil engineering curriculum). In this sense, future research should include control groups that utilize traditional methodologies compared with Game Theory’s applications in the classroom, not only in civil engineering programs but also in other undergraduate and graduate engineering courses.