New benchmark results for the stochastic resource-constrained scheduling problem

A project is a temporary endeavor to achieve clearly defined goals. Project management deals with the planning, organization, execution, monitoring (controlling) and closing of a project in order to attain the project's objectives [42]. A project entails a set of activities that have to be executed while respecting precedence constraints and resource and time limitations. Project scheduling belongs to the planning phase of project management, in which a schedule is developed that decides when to start andfinish the activities in order to achieve the project's goals. Practical project management is usually confronted with scarceness of the resources available for processing the activities. Over the last decades, this has given rise to a large body of literature on resource-constrained project scheduling, with the so-called resource-constrained project scheduling problem (RCPSP) as a central problem. In practice some of the scheduling parameters may be uncertain. The exact duration of an activity, for instance, might not be known at the beginning of the project. One of the earliest sources for this observation is Malcolm et al. [37]. Similarly, the number of available resources is another parameter that may not be known before project execution.