ABSTRACT
The theory of constraints is playing an important significance in the operation of new Enterprise Information System, because of its modify effect to ERP/MRPII. DBR approach is the management tool of TOC when applied to an production system. DBR production systems as TOC's core content, plays an extremely important role. The paper will do a detailed study for one key issues of DBR-the determination of buffer size, in order to perfect DBR technology. Use queuing theory to model the production networks with machine failures, batch service and varying transfer batch sizes, and estimates the average flow time of product in the upstream processes before bottlenecks and assembly and the standard deviation of flow time, and then we can calculate the size of time buffer.
