The paper investigates analytical approaches to model, analyse and optimize the reliability of production lines (PLs). A PLis an important part of the computer integrated manufacturing system(CIMS). It is defined as a network of computer-comtrolled stages through which parts are successively fed. Each stage is only one machine or a processing centre of several machines. The production process is driven by a series of discrete events, for instance, stage break down, failure repair and completion of processing. The interaction and interference among these events are so complicated that there are lack of effective modelling methods to analyse and evaluate the reliability of PLs. Besides, PLs have their own features which make their reliability analysis different from that of the electronic system or the control system. Among these characteristics are flow on line, blocking and starvation of stages due to limited buffers. In this paper, first presented is a survey and systematic classification of the literature relevant to PL reliability. Then, a variety of analytical approaches are developed to calculate availability ad through -put of different types of PLs. The main work can be summarized as follows. 1. Modelling and analysing the reliability of directly interconnected PLs (without internal buffers). First, some general theorems for line performance measures are derived, and upper and lower bounds are formulated. Then, discrete PLs are discussed in detail using renewal processes. In -eluded are series, parallel, series-parallel, parallel-series, stand-by, and splitting and k out of n (F) PLs. the analytical results for contineous and stochstic PLs are obtained through Markovian theory. 2. Modelling and analysing the reliability of flexiblized PLs (with internal buffers). Employing the supplementary variable technique, a concise and practical analytical solution in closed-form is derived for two-stage PL. Using Markovian combinatorial state discription, the reduntant PL is evaluated and the analytic results are compared. Finally, a model for determining the performance of three-stage flexible PL with reworking and scrapping is presented. 3. Modelling and analysing the reliability of multi-stage PLs (with internal buffers). 1 *. after approximating machine failure and blocking, the multi-stage PLs are modeled using queueing network theory. The model is extended to suit for a tandem line (in which each stage consists of a group of parallel machines), a splitting line and a merging line.2 *. Based on the flow equilibrium in the production process, a set of siultaneous differential equations are derived. The number of the equations is linear with the size of PLs. This indicates the readily computational property. The method is also applied to assembly, a disassembly, a circular line, splitting line and general production net- works.3 *. A linear model is proposed for the deterministic N * M
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