A new approach for material ordering and multi-mode resource constraint project scheduling problem in a multi-site context under interval-valued fuzzy uncertainty

摘要

Taking both material procurement and project scheduling problem simultaneously has been proved the most noteworthy areas in project management. The ordering amount is a key factor due to the fact that through keeping a full stock of required materials, the probability of material shortage and corresponding inefficiency decline but the costs of inventory holding increase significantly. Besides, the delay in individual activities and consequently in project completion increase if a small amount of needed material is purchased. The multi-site context as one of the new resource constraint project scheduling problem (RCPSP) extensions has been widely utilized in some applications in real-world cases, especially in construction projects. In this paper, a new mathematical model is proposed for the combination of ordering problems considering all-unit discount policy and multi-mode RCPSP (MRCPSP) in the multi-site context. The developed model aims to minimize the project total cost as well as the completion time of the project. In the novel proposed mathematical model, the transportation time is crucial and depends on the site that activities are assigned. With respect to the inherent uncertainties in project management, the duration of activities, transportation time between sites, and lead time are regarded as triangular interval-valued fuzzy numbers. In addition, a new hybrid multi-objective uncertainty approach is presented to handle interval-valued fuzzy mathematical model. The results obtained by solving the presented model employing an application example from MPSPLIB data set and a real case study about seawater intake systems are appraised considering key parameters to validate the proposed model and provide some managerial insights.