Determining the timing of project control points using a probabilistic location model

Most of the projects are executed in volatile environments . In such an environment , changes to the project plan are inevitable . The dynamic nature and the changes in the environmental conditions or unforeseen events will no doubt cause some deviations from the plan . Rarely does a project manager finish a project with the same project plan as established in the final stage of the planning phase . If a project manager does not have a formal process for reviewing , evaluating , and approving any such changes the resulting impact will be uncontrolled scope variances . Therefore , the project manager needs to continuously supervise the project’s progress. Control process can be assumed as a continuum in which one side is continuous control and the other side is no-control . Although continuous control is the most efficient type of project control butcost-wise is prohibited . Implementing no-control policy may also be costly due to the possible enalties imposed on late delivery of the project and other losses due to not being able to deliver the project within the specified criterion . As such , the project manager has to perform the controlling actions at some discrete points during the project life cycle . Approaches with a static view of the project control especially in long projects suffer from the fact that the possibility of corrective actions is missing . In these approaches, it is assumed that the possible deviations from the plan are corrected simply by imposing a penalty . Therefore according to some project characteristic such as volumes ofthe work being done some control points are specified a priori.In this paper , we use a probabilistic facility location model to find optimal time of control points. In the proposed approach , after determining a control point and distinguish the deviations from the project plan, we update the plan respectively . After updating the project s plan , we determine the next project control point for the rest of the project , if necessary . This process continues until the end of the project and by reactive scheduling , we try to determine control points dynamically.

Keywords:

Project control , Probabilistic facility location model , Dynamic control