Optimizing project selection and scheduling problems with time-dependent resource constraints

This study presents an optimization model using constraint programming (CP) for project selection and scheduling problems with time-dependent resource constraints. A generic model is proposed to maximize the total profit of selected projects for construction and R&D departments given scheduling problems with various resource constraints during specified time intervals, including consumed and renewable resource limitations. Due to different periodical procurement strategies and annual budget concerns, this research considers various practical limitations for scheduling and allocating resources, such as budget limitations and resource constraints. For additional practicality, the optimization model integrates a project selection mechanism, scheduling precedence, and relationships between projects. To illustrate the model capabilities for solving project selection and scheduling problems, the current study presents two scenarios for maximizing profit, including fifteen candidate projects with time-dependent resource constraints. Analysis results demonstrate that the proposed model allows planners to determine an optimal portfolio with specified resource constraints according to various time intervals, and benefits decision-making for project selection and scheduling. (C) 2011 Elsevier B.V. All rights reserved.