12 / 2019-01-12 14:37:01

A New Project Scheduling Control Method based on Activity Quantities

Schedule control,Earned Value Management,Earned Schedule Management,Earned Duration Management,Quantity Survey

The Earned Value Management (EVM) has been adopted for project schedule control in traditional project management practice. However, previous studies found that EVM suffers in some theoretical weaknesses, e.g., highly influenced by costly activities; and the final schedule performance will resume to the baseline, no matter how poor the schedule performance was for the activity. New method such as Earned Schedule Management (ESM) and Earned Duration Management (EDM) were proposed to improve the traditional EVM. However, ESM and EDM still adopt the basis of Planned Value (PV) and Earned Value (EV) for the overall project. They ignore the impact of individual critical paths to the project completion date, and tend to mislead the manager’s conception of de facto schedule performance. To attack the abovementioned problems of traditional EVM, ESM and EDM, the current research proposes a new schedule control method, namely the Quantity-based Project Schedule Management Model (Q-PSMM), which adopts the concepts of EDM, but calculates the project schedule performance based on ‘activity quantities’ of the critical path instead of the overall ‘activity values’ in the traditional EVM. The proposed Q-PSMM calculates the required residual duration of an activity using the quantity information and compute the project’s ‘Estimate to Complete (ETC)’ duration using critical path method; finally, the overall project schedule performance index is evaluated based on the information of current schedule, project ETC duration and project planned duration. According to the result of case study, the proposed Q-PSMM is proved to reflect the impact of critical activities in the project schedule performance more effectively; it also provides information for planning of schedule improvement strategies. It is concluded that the proposed Q-PSMM has the potential to improve the theoretical weaknesses of the traditional project schedule management methods (e.g., EVM, ESM and EDM) and provide a more useful and effective tool for schedule control of construction projects.