Production Rate Estimation of Series-parallel Production Line with Multiple Failure Modes

An analytical model was proposed to estimate the production rate of series-parallel production line. Each machine has both operation dependent failure (ODF) and time dependent failure (TDF). Machine states include operation, ODF, TDF and ODF&TDF. First, the machine states space and transition relations were defined. The two-workstation line performance evaluation method was established based on discrete state Markov chain, and this method was used as a building block of the decomposition method. The whole line production rate was estimated through iterative calculation of the decomposition method. In order to improve the efficiency, a set of parallel machines were replaced with an equivalent machine. Several numerical examples and an actual production line case were carried out to demonstrate the accuracy and efficiency of the proposed method.