Proactive and Reactive Constraint Programming for Stochastic Project Scheduling with Maximal Time-Lags

TL;DR

This paper compares proactive and reactive constraint programming strategies for stochastic project scheduling with maximal time lags, introducing new methods and analyzing their performance.

Contribution

It presents a new fully proactive CP-based method, constructs a reactive approach with online rescheduling, and utilizes STNUs for partial order schedules.

Findings

STNU-based algorithm yields best solution quality

STNU approach has favorable offline and online computation times

Comparison highlights advantages of different scheduling strategies

Abstract

This study investigates scheduling strategies for the stochastic resource-constrained project scheduling problem with maximal time lags (SRCPSP/max)). Recent advances in Constraint Programming (CP) and Temporal Networks have reinvoked interest in evaluating the advantages and drawbacks of various proactive and reactive scheduling methods. First, we present a new, CP-based fully proactive method. Second, we show how a reactive approach can be constructed using an online rescheduling procedure. A third contribution is based on partial order schedules and uses Simple Temporal Networks with Uncertainty (STNUs). Our statistical analysis shows that the STNU-based algorithm performs best in terms of solution quality, while also showing good relative offline and online computation time.