Project Portfolio Optimization under Temporal Constraints with uncertainty

The definition of more realistic scenarios of instances for the Project Portfolio Optimization (PPO) of new product developments usually should involve precedence relations that generate effects related to time-interdependence among different projects. The study of time -interdependences, or time effects, on the selection of projects captures our attention because they affect the problem objective functions. Three different moments have been identified as usually present in any project: 1) the estimated completion time; 2) the moment in which the competence become significant; and, 3) the moment in which the developed product becomes old. A PPO under such temporal constraints (denoted PPOTC) could face risk because the lack of reliable data derived from long lead times of projects, or by a complex market and technology dynamics; such imperfect knowledge could cause variability in the benefits and requirements of a PPOTC. In this sense, this research proposes the design of a methodology based on intervals for PPOTC under uncertainty, and the study of their influence in choosing optimal project portfolios of new product developments. The advantage of this approach is a unified and simple way to model the different sources of imprecision, uncertainty and arbitrariness. Also, the model is parametrized such that the attitude of the DM facing the imperfect knowledge can be adjusted by using two meaningful parameters.