Uncertainty and schedule instability in supply chain: insights from case studies

With increasing uncertainty of business environment, schedule instability is a major issue in most manufacturing companies. Academic research on schedule instability has been conducted for more than three decades but results have been dispersed and not well integrated. The objective of this paper is to present a framework and obtain insights of strategies the manufacturing companies applied to deal with schedule instability. To aid in conducting the empirical study, the framework of schedule instability has been developed. It attempts to relate the factors and impacts as well as the two types of strategies to deal with schedule instability. Four case studies have been conducted. We present three propositions from this study which extend the debate of schedule instability from more technical and operational aspects such as lot sizing and planning issues to relationships and design aspects. The findings imply that, in dealing with schedule instability, managers should not only focus on buffering and other reactive strategies, but also move toward better cross-functional team, supply chain collaboration, and proactively designing better flexibility in the supply chain.