چکیده:
In the process of project planning, resource over-allocation is a major shortcoming. The resource over-allocation causes the schedules not to be applicable in practice. Besides, in real projects, it is hard to predict the duration of activities since they may be changed due to lack of resources, delays in delivering resources, unskilled workers etc. that make activities not to be completed as predicted. Hence, it is important to develop a method that can schedule activities by considering different execution conditions. In this research, we focused on another aspect of solving resource over-allocation problem by considering uncertain activity duration. For this purpose, a mixed integer programming model is developed where the objective function is maximizing net present value of the project while duration of activities are not deterministic. Then a number of examples are solved using a heuristic algorithm. The results show that the proposed algorithm can effectively solve the case studies with no over-allocated resources. Afterward, the algorithm is solved using the data of constructing a hospital. The results reveal that the algorithm can be successfully used for real projects.
خلاصه ماشینی:
com An Applicable Heuristic for Scheduling Multi-mode Resource Constraint Projects Using PERT Technique in the Presence of Uncertain Duration of Activities Aidin Delgoshaei a,b*, Masih Parvin b, Ahad Ali c and Maryam Ghoreishi d a Department of Industrial Engineering, Faculty of Engineering, Kharazmi University, Tehran, Iran b Faculty of Engineering, university of Putra Malaysia, Serdang, Kuala Lumpur, Malaysia c Department of Mechanical Engineering, Lawrence Technological University, Southfield, Michigan, USA d Department of Economics and Business, BSS, Aarhus University, Aarhus, Denmark Abstract In the process of project planning, resource over-allocation is a major shortcoming.
In multi-mode resource constraint project scheduling problems (MRCPSP), activities are not forced to be executed in only one way.
Thus, in the present study, a new method for scheduling resource constraint projects while durations of activities are not certain is proposed.
1. Index i is used for showing number of activities k is used for showing number of resource types t is used for showing time slots m is used for showing modes of activities (View the image of this page) shows the capacity of resource type K r(i, k) indicates the required resource type � for performing activity � D(i,m) is duration of Activity � using m th mode that is estimated using triangular probability function: (View the image of this page) (Binary) In this part a NL-MIP model is developed for maximizing NPV of the project while both positive and negative cash flows are taken into account and durations of activities are considered uncertain.