Balancing Time and Quality Cost in Using Corner Cutters in Composite Roofs

Abstract

Time, cost, and quality are the main goals of any project. Project managers have been focused on reducing time and cost in projects since the late 1950s, when the critical path was first expressed, and thus the issue of time-cost balance arose. In recent years, the attention of project managers to reducing project execution time while obtaining the desired quality for the project has increased. This has led researchers to develop time-cost balance models that include the quality factor. In this research, the issue of time, cost, and quality balance was studied, assuming that the quality of project activities depends on time and cost. For this purpose, a three-objective planning model was formulated, considering time, cost, and quality as objective functions and considering prerequisite relationships. A fuzzy decision-making approach was used to solve the problem. In order to implement this approach, the execution time and cost of compressing time and improving the quality of activities were described as fuzzy ideals so that a fuzzy decision-making approach could be used to balance them with quality. Combining membership functions related to the execution time of individual activities and membership functions of fuzzy ideals related to project execution time and compression cost, in line with the fuzzy decision approach, led to a one-objective planning model. To demonstrate the efficiency of the proposed model and approach to solving a real problem of time balance, cost, and quality related to time balance, the cost of using angles in composite ceilings was solved and the results were discussed. Finally, the validity of the models was evaluated using parametric analysis. To further adapt the proposed model and solution model to reality, nonlinear membership functions can be used instead of linear membership functions to describe quality dependence on time and even fuzzy ideals related to execution time and compression cost.