Project portfolio selection under skill development

Abstract

This chapter surveys models for project portfolio selection that incorporate the development of skills by learning and/or forgetting. Basic learning models (starting with Wright’s learning curve) are recapitulated and their relations are discussed. Attention is given to simple exponential as well as to S-shaped learning curves or laws derived from inventory-like considerations. Moreover, it is shown how these models have been used by diverse authors as components of approaches to support staffing and scheduling decisions. Then, the integration of learning and forgetting within models for project selection is described in more detail by providing mathematical programming formulations, discussing approximations, and outlining numerical solution techniques. Also analytical results on optimal project portfolio selection over time are recalled. The survey discusses both, models where skill development goals are formulated as objectives, and models where they are used as constraints. Multi-objective formulations and corresponding solution techniques are outlined as well. Skill-based project selection under uncertainty is identified as a major open issue for future research.