Performance Evaluation Of Hybrid Production-line Systems Consisting Of Two Machines

Due to the aggravating competition of the worldwide market, advancing technology, accelerating production proliferation, increasing demand of production diversity, etc, the fashion of the diversity and small batch has been becoming the leading mode of production. Morden manufacturing is increasingly tend to new production mode of flexible, according to the market requirement or the order of the products to make production schedules.With the change of the production mode, if the enterprises want to survive and self-development in the competitive market, they must strengthen the competition advantages and the ability to adapt to the capricious market. However, uncertainties of the production, various stochastic factors, unideal mathematical models and undeveloped computation technoques, etc, bring the difficulty in handling the problem. In order to adapt to these changes, you must analysis the performance of the production lines of the enterprises.The main contributions of the dissertation are as follows:1. the dissertation studied background of the thesis, then I make a brief introduction on the basic notions of unreliable production lines, reviewed the developments and research situation of unreliable production lines and point out some deficiencies and future research directions.2. In accordance with a hybrid production line system consisting of two machiens subjected to independent failure modes and unreliable buffer is considered, average thoughput and average buffer level are the parameters to be evaluated, based on discrete model, the states transition probabilities of the system are studied analytically, according to the guess of the form that internal state probabilities should assume, reducing the difficuities of solving the problem, a corresponding algorithm are developed here , and also the corresponding program is provided.3. A hybrid production line system consisting of machines subjected to non-independent failure modes and unreliable buffer is studied, unreliable buffer and machines with three states, namely, perfect states, usable states and failure state, and the perfect state can transfer to usable state is considered. based on discrete model, according to the deal with the states probabilities related to machines and buffer, a corresponding algorithm are developed to evaluate the performance of hybrid production systems, and an approximate technique and the corresponding program are also supplied here. 4. A hybrid production line system consisting of Machines subjected to non-independent failure modes and pre-maintenance is considered. Machines have three states, namely, perfect state, usable state and failure state, the states of the machines can transfer to each other, and the buffer is unreliable. Based on discrete model, a new algorithm for generating the transition matrix is proposed, the algorithm uses the transition matrix that correspond to a certain value, this process avoids the need to record explicitly all the states and transitions of the model, which is tedious and time-consuming especially for large values of the buffer level.5. A brief summary of this thesis and the follow-up work is viewed.