Managers of multiple projects with overly constrained resources face difficult decisions in how to allocate resources to minimize the average delay per project or the time to complete the whole set of projects. We address the static resource‐constrained multi‐project scheduling problem (RCMPSP) with two lateness objectives, project lateness and portfolio lateness. In this context, past research has reported conflicting results on the performance of activity priority rule heuristics and does not provide managers with clear guidance on which rule to use in various situations. Using recently improved measures for RCMPSP characteristics, we conducted a comprehensive analysis of 20 priority rules on 12,320 test problems generated to the specifications of project‐, activity‐, and resource‐related characteristics–including network complexity and resource distribution and contention. We found several situations in which widely advocated priority rules perform poorly. We also confirmed that portfolio managers and project managers will prefer different priority rules depending on their local or global objectives. We summarize our results in two decision tables, the practical use of which requires managers to do only a rough, qualitative characterization of their projects in terms of complexity, degree of resource contention, and resource distribution.
