Providing a Method to Buffer Sizing Determination in Critical Chain of Project Scheduling (Case study: Suliran Co.)

The critical chain is a novel approach in the domain of project managementwhich has been developed to eliminate projects unfavorable impacts and theirreasons. Also, it is used to increase resources performance and to utilizerestrictions of project system. To secure project against probable disturbancestime buffers were installed in different areas based on this approach. Thus,tensions of uncritical activities were kept to be transferred to critical chain andtensions of critical chain activities were prevented as well to be transmitted to project delivery time. In the present paper, a method to determine buffers size in the domain of critical chain was presented. The method fortified with such main characteristics as applying experts ideas throughout the work steps, as well as simple implementing process. Even though, the concepts proposed in this method are close to Pert method, the distribution function of activities time probability in the method was obtained according to experts ideas. Finally, the critical chain was conducted for designing, constructing, and installing of a steel structure in Suliran Company to assess the suggested method. Buffers size were estimated using two recognized methods in literatures, Cut and Paste (C&P) method, Root Square Error (RSE) method and the proposed method. Comparing with two mentioned methods, the presented method, as obtained results display, generates buffers with more protection against project's probable delays.