Heuristic methods for finance-based and resource-constrained project scheduling problem

Contractors are often simultaneously subject to capital shortages and resource scarcities in construction projects, forcing them to rely on loans to offset cash deficits during project execution. However, few studies have proposed exact or heuristic methods to deal with the financed-based and resource-constrained project scheduling problem (FBRCPSP). This study aims at developing flexible heuristics for the FBRCPSP. To address the FBRCPSP, a mathematical model is first constructed to maximize a project's profit considering financing costs, then modified serial schedule scheme (MSSGS) and modified parallel schedule scheme (MPSGS) heuristics are designed to gain a feasible project schedule and its financial plan while complying with feasibilities of the precedence relationship, resource constraints, and credit limits concurrently. Moreover, the proposed heuristics, implemented as part of a genetic algorithm (heuristics-based GA) can be applied to solve the optimization model of the FBRCPSP. In two case studies, the results showed that the heuristics-based GA adequately explored the feasible solution space so that it could obtain the best solutions near those from the integer programming (IP) technique (By optimization software CPLEX version 12.8) and outperformed the previous precedence-preserving GA in terms of solution quality and computational time. Finally, the developed heuristics can devise or update schedules and the corresponding cash flow and resource-demand profiles, helping practitioners achieve expected profits and implement project control.