Reviving a mechanistic view of CPM schedules in the age of information technology

This paper argues for reviving a more mechanistic view of CPM (critical-path-method) scheduling. It first reviews the clarity of displaying both the time and logic information of schedules in the graphics outputs of scheduling software used in construction practice. While such software offers an abundance of features, the true nature of schedules may remain hidden behind graphics defaults. Two methods introduced in the literature, fenced bar charts and a mechanical model, are then brought forth as examples of techniques supporting an intuitive structural understanding of schedules. Both stress the equal importance of activities and logic links for displaying schedules. Comparisons between these mechanistic methods and scheduling software are drawn and recommendations for achieving optimum graphical representations of schedules are provided. Eventually, a revised approach that acknowledges the complexity of schedules and the need for their unambiguous display can contribute to reducing errors and to an overall improved use of CPM scheduling