Analysis of a buffered two-machine production line with unreliable machines

Serial production lines are a fundamental kind of production systems. The two-machine line models are often used as a building block to analyze and develop approximation methods more complex production systems. In this context, the addressed paper deals with a new analytical formulation to evaluate the system throughput of a two-machine production line considering the general case where the two machines have different processing, failure and repair rates. Both processing and reliability parameters are assumed to be independent and exponentially distributed. The proposed method is based on the analysis of the different states of each buffer using birth-death Markov processes. Then, each original machine is replaced by an equivalent one taking into account the probabilities of blockage and starvation. A comparative study based on different test instances existing in the literature is presented and discussed. The obtained results prove the effectiveness and the accuracy of the proposed method comparing with existing models in the literature. © 2014 Old City Publishing, Inc.