Project Tightness (PT): A Complementary Topological Indicator for Explaining Project Schedule Behaviour

Abstract

The paper introduces Project Tightness (PT) as a topological indicator that captures the temporal tension of project networks and complements the traditional Series–Parallel (SP) index. Through simulation studies, the results show that PT helps explain differences in variance propagation and control performance among projects with similar structures. Overall, combining PT and SP provides a more complete understanding of project behaviour under uncertainty.