System reliability for a multi-state manufacturing network with joint buffer stations

This paper studies system reliability for a multi-state manufacturing network with multiple production lines (MSMN-MPL) considering joint buffer station. Joint buffer stations with finite volumes are set into the MSMN-MPL to temporally store blocked outputs from upstream workstations. The usage volume of each joint buffer station is therefore affected by the capacity states of workstations. An adjustment term, defined as the probability that all buffer stations are not blocked, is proposed to analyze volume usage and corresponding probability for joint buffer stations. The system reliability with finite buffer volume is evaluated accurately in terms of the adjustment term. In particular, the relationship between system reliabilities with infinite and finite buffer volumes can be formulated by multiplying the adjustment term. A practical case of footwear manufacturing system is utilized to demonstrate system reliability evaluation with both infinite and finite buffer volumes. The suggested production policy for the case is to produce 144 and 96 products by two production lines because this policy can result a higher reliability. Moreover, experimental results show that the system reliabilities with infinite and finite buffer volume are 87.190% and 83.099%, respectively. This indicates that the assumption of infinite buffer volume overestimates the system reliability in the footwear manufacturing system.