Project schedule contingency planning: Building on von Bertalanffy's open systems theory and critical systems practice

The research on project schedule contingency suffers from three major shortcomings: (1) it only partly reflects the complexity arising from the high interdependencies among project activities; (2) it is predicated on the idea of closed systems and thus does not address the interaction between a project and its environment; and (3) it does not sufficiently inform industry practices. This paper addresses these gaps by conceptually and analytically linking von Bertalanffy's open systems theory and critical systems practice (CSP) to schedule contingency planning. It focuses on buffer management as a common approach to schedule contingency planning and accordingly develops a method to determine the size of time buffers based on the three foundational dimensions of open systems theory. Further, this research provides guidelines to explain how the simultaneous pursuit of the four stages of CSP can assist project managers and decision-makers in responding to disruptive events.