Slip chart-inspired project schedule diagramming: Origins, buffers, and extension to linear schedules

Linear schedules continue to hold significant potential for planning and control in construction project management, where work progress of activities is often repetitive in nature. However, linear schedules are limited in graphical comparisons. A slip chart from the aerospace industry, which recorded launch dates on two axes of time, is rediscovered as inspiration for an improved tool. However, whereas its original form could only track points in time, schedule activities must be represented as ranges across time. Therefore, additional theory is needed to extend slip charts toward being able to handle linear schedules. To create such a layout, this research systematically extends its conventions and capabilities. A conversion algorithm for linear schedules is derived. New features are introduced for a comprehensive approach. In particular, buffers that represent minimum and also maximum constraints between activities are investigated and converted. Criticality and float are defined.