Efficient priority rules for the resource-constrained project scheduling problem

Resource-constrained project scheduling is a core problem for many industrial applications, e.g. finite scheduling systems and the planning of business re-engeneering processes. In order to solve these problems commercial systems employ classical priority rules. We review one of them, the well-known RSM priority rule. A detailed analysis of this rule reveals that it does not reflect the finite capacity of resources properly. Consequently, this leads to poor solutions. Hence, an improved RSM priority rule is derived and two new priority rules are developed which extend the well-known precedence based Minimum SLacK priority rule (MSLK) to a precedence and resource based slack priority rule, respectively. On the basis of a comprehensive experimental investigation we provide new insight into the performance of classical and new rules. Furthermore, we show that one of the new rules is significantly better than the classical rules and hence should be employed in project scheduling systems.