Identifying, framing and managing uncertainties in project portfolios

•Organizational complexity, environment and projects cause portfolio uncertainty.•Managers frame portfolio uncertainties into opportunities, threats and neutral.•Uncertainties can be managed using rational, structural and cultural mechanisms.•Managers perceive portfolio uncertainties more often as threats than opportunities.•The use of rational control mechanisms dominates in uncertainty management.

Uncertainties in the organization, external environment and from single projects may hamper project portfolio performance unless managed properly. This paper introduces a framework on uncertainties and their management in project portfolios and pursues increased understanding on how managers can take uncertainty into account better. We explore uncertainties, how managers frame them as opportunities or threats, and the actual practice of managing them across ten R&D project portfolios. The framework on project portfolio uncertainties and their management is further refined based on the empirical results. As key contributions, we show evidence on the balanced existence of three types of uncertainties, the threat bias in their framing, and the dominance of rational, opportunity driven mechanisms of control in uncertainty management. We discuss the context-dependent practice of project portfolio management and the need to complement rational mechanisms with structural and cultural, for project portfolio management to become a dynamic capability.