Critical chain scheduling: a new approach for feeding buffer sizing

Critical chain techniques for overcoming uncertainty which exist in a project, offers that buffers are added at the end of critical chain and feed chains. The key point is amount of the buffer size, because even bad buffer size causes the loss of critical chain technique in philosophy. Although with a large buffer size consideration project is protected from uncertainties, this causes longer lead time and inefficient use of this technique. Small size selection of the project buffer does not protect it against uncertainty. In this research, an effective method for determining the buffer size based on post density factor with regard to limit resources, location of task in a network, environmental risks and risk of each task is proposed. Effectiveness of the proposed method compared with the C&P method and RSEM and APRT and APD. Simulation results show that it could be used as suitable method for specifying size of buffer.