Generating a robust baseline schedule for the robust discrete time/resource trade-off problem under work content uncertainty

Abstract

As a subproblem of the multi-mode resource-constrained project scheduling problem, the discrete time/resource trade-off problem (DTRTP) has occurred widely in practice. This paper tries to generate a robust schedule for the DTRTP with a given due date under uncertainty of the work content. Nine free slack-based measures are adopted as surrogate measures of solution robustness, and a two-stage algorithm based on differential evolution (DE) and the time buffering approach are proposed to deal with the robust model based on the proposed nine different surrogate measures. The computational results show that the three robust models based on a free slack utility function have been proven to be more effective and could generate more robust baseline schedules in most projects with excellent performance, i.e. a low stability cost, a low average project length and a high timely project completion probability.