Extending project time–cost analysis by removing precedence relationships and task streaming

Faster completion of projects continues to be an important problem in project management. The traditional approach to reduce completion time has been to shorten the time required for performing a particular activity, often called crashing. In this paper, we propose the addition of two related approaches to expedite a project: increasing the parallel processing of tasks by completely removing precedence relationships, or streaming tasks by fractionally removing precedence relationships. We present a quadratic mixed integer programming approach for reducing project completion time that considers crashing as well as the removal and modification of precedence relationships. Our model extends the linear formulation of the deadline time–cost problem. Two examples are presented to illustrate the suggested approach. Project managers who wish to expedite their projects are advised to consider the benefits and costs of doing more tasks concurrently, or overlapping them, in addition to compressing task times. 2006 Elsevier Ltd and IPMA. All rights reserved.