Formalization of project portfolio management: The moderating role of project portfolio complexity

Companies frequently implement formalization to improve success. Previous research has found supporting evidence for the performance-enhancing effects of formalization in both single project management and project portfolio management. However, there is no research on how formalization at the project level interacts with formalization at the portfolio level, or on how this interaction may impact success. This study investigates the interaction of formalization at both levels and examines the moderating effect of project portfolio complexity on formalization. Using a sample of 134 firms, this study shows that single project management formalization and, likewise, portfolio management formalization are directly connected to portfolio success. Simultaneous formalization at these two levels delivers a complementary effect, resulting in an increase in success that is more than additive. A contingency analysis confirms that the proposed positive effects become more prominent if complexity is high. Complexity measured as project interdependency has a stronger moderating effect than complexity measured as portfolio size.