Sharif Digital Repository

The main goal of this thesis is to reduce the gap between the theoretical and actual project scheduling problems by introducing three problems and then proposing three different exact and meta-heuristic algorithms to solve them. These problems are as follows: the Resource-Constrained Project Scheduling Problem with Minimization of Total Weighted Resource Tardiness Penalty Costs (RCPSP-TWRTPC), the Resource-Constrained Project Scheduling Problem with Discounted Cash Flows of Weighted Earliness-Tardiness Costs (RCPSP-DCWET), and the Multi-Mode Resource-Constrained Project Scheduling Problem with Minimization of Total Weighted Resource Tardiness Penalty Costs (MRCPSP-TWRTPC). Also, we develop a... 

The focus of this research is to present a model to verify the acceptance of projects with time and cost dependency on the usage of equipments. Decision on these projects is based on a dynamic programming in which at each stage, the profit of available projects in this stage, equipment value and the best choice of future stage are decision keys. In other words, after the completion of a project, it should be decided between doing a project or selling the equipment and leaving the remaining projects. For each projects, there is a product network that includes projects jobs and operations. After accepting projects, equipments of the projects will not be renewed and the usage of the equipments... 

This study focuses on two-machine flow shop problem where processing times are uncertain and the objective function is makespan. All information available about the processing time is an upper and lower bound and also expected value. The min-max and min-max regret version of the problem are adopted. In this study, in order to control the degree of conservatism of the solution, we suppose in each scenario the number of processing times on each machine that can deviate from its expected value is controllable. By considering the duality theorem, we present a mixed-integer programming model for the min-max problem. For each of two problems, we present an algorithm for finding objective value. We... 

More than 60% of sales account for materials, and so the roles and responsibilities of the material managers have been recognized as more important within a firm or in a large scale project than before. However, in many purchasing situations, different considerations conflict with one another. In these situations material planning plays an essential role in the total cost minimization process. Here, the optimal material ordering policy for an item in a deterministic time-phased demand environment with all-units discount in purchasing is considered. Based on proven properties of the optimal order policy, a tree search procedure is designed to construct sequences of orders in the optimal... 

Among various types of resources defined in the project scheduling literature, the most studies have been conducted on the renewable and nonrenewable resource types. Definition of different resources in the project scheduling literature is based on the specification of the resources in the real projects. Yet there are some sort of nonrenewable resources in the real projects that are not exactly similar to the type defined in the project scheduling literature. The difference stems from this fact that in the project scheduling literature, it is supposed that the nonrenewable resources required for the execution of the project activities are available in full amount at the beginning of the...