An efficient solution for determining location and size of buffer stocks

An automated transfer line is a production system which is susceptible to failure and breakdowns. Any failure of one workstation usually disables the entire line resulting in the loss of production and decline in the system efficiency and reliability. To overcome this difficulty, the insertion of buffer stock(s) in the transfer line is proposed. This process requires a complete technical and economic analysis. In the literature, this analysis was conducted by analytical and traditional simulation methods. This paper utilizes the Monte Carlo simulation as the basis of analysis to a switch assembly transfer line. Extensive data were gathered to develop downtime distribution in hours, downtime probability distribution, and downtime cumulative probability distribution. These data were used to calculate the line efficiency and actual average production rate under the current operations. A complete analysis was performed to determine the optimum locations of buffer stocks. The introduction of two buffer stocks in the three-stage switch assembly line resulted in considerable improvement in the line efficiency and production rate. By using an iteration process, the size of the buffer stocks was determined as well. In conclusion, a comparison between the current and proposed operations is offered; and the areas of improvement are highlighted.