Availability modelling and analysis of multi-product flexible transfer lines subject to random failures

Product requirements have changed dramatically in today's industries forcing companies to implement flexible transfer lines manufacturing diverse product types. However, most of the researches dealing with transfer lines are so far limited to the mono-product and homogeneous lines (i.e., perfectly balanced). This paper addresses the problem of estimating the performance of multi-product, flexible transfer lines. Such lines are composed of several machines in series and can be used to manufacture a variety of products in a batch production environment. The machines are subject to random operation-dependent failures, and there are no intermediate buffers between adjacent machines. This paper aims to propose an analytical model for assessing the steady-state availability of such lines. A simulation model is also developed to mimic the real dynamic behaviour of flexible transfer lines. Thousands of production line configurations are tested in order to compare analytical results with simulation results. We used statistical tests to prove that the proposed formulae are exact and robust to model the steady-state availability of multi-product, unbuffered, flexible transfer lines subject to random failures.