Mission Reliability Of Quick Researching And Manufacturing System With Consideration Of Design Iterations

The quick researching and manufacturing system (QRMS) with high reliability can quicken the equipment development, and give a quick response to the need of customers. Design iterations are one of important factors that influence the mission reliability in the development process of a project. When design iteration is considered in mission reliability, the mission process is variable and the demand for resource is stochastic, so new indexes and models need to be built. In this paper, the main representation formations of design iterations are analyzed, and the mission reliability modeling and analysis method of QRMS is studied with consideration of design iterations.Firstly, to satisfy the requirements of QRMS evaluation, the reliability index for QRMS is given.Secondly, mission reliability of QRMS without consideration of resource conflict is studied. The computing methods of the mission reliability of QRMS are described where single design iteration occurred. Based on above, in order to describe a series of iterations that may occur in QRMS, from the perspective of task delayed by failures, the time-delayed net is promoted and the corresponding algorithm for its mission reliability named the two-time BDD algorithm is also given. This model substitute the time of design iteration with the work time of the fault joint, which simplified the difficulty in evaluating the mission reliability of QRMS.Thirdly, mission reliability of QRMS with consideration of resource conflict is studied. The design structure matrix is used to describe the design iterations, the Markov queuing network model of QRMS and the corresponding algorithm are presented to evaluate mission reliability parameter. Based on the influence of mission accepted strategy on the ratio of delayed time of missions, the analytical model of accepted strategy for QRMS is given, and you can gain the maximum profit expectation by applying the accepted strategy result described above.Fourthly, in the situation of consideration of complex mission process, interaction in design iteration and the serve time in common distribution, the analytical model is not easy to build. The simulation models are built in different situation respectively. In building the simulation models for manufacturing missions, based on the combination with the multi-agent method and the GOOPN method, the compoundable method is presented, which makes the models more intelligent. Based on the result above, combined with the GOOPN models and the GERTS model, we put forward EPN-GERTS model through embedding Petri net into GERTS model, which can simplify the complexity in building models, and also improve the defects of GERTS model in describing resource conflicts and Petri net model in building models. In building the simulation models for development missions, the improved GERTS model is present to describe the development processes in QRMS. Through dynamically computing the redo times in GERTS, the improved model can reflect the operation character of development process. The simulation results are more precise when we use the models above.Lastly, modeling, analysis and simulation software of QRMS, which called QRMS-SIM, are developed with a character of consideration the influence by life state of equipment, by which the defection of the equipment postulated to be new in simulation is eliminated. An example, which based on a QRMS in developing engine, is also given.