Fuzzy Set Theory Applied Research In Production Planning And Scheduling

Morden production system is a complicated large —scale system which contains man, meterials, equipments and so on. The outside and inside fac-fors influencing the efficacy of the system are lots of uncentain and fuzzy factors , and the planning and scheduling is very complicated. By making use of the theory and method of fuzzy sets, the thesis describes the various uncertain and fuzzy factors exsisting in the practical production, then immitates the decision—making procedure to set up a fuzzy model with fuzzy parameters , and to give its solutions. At first, it discusses the general step of fuzzy control method of the aggregate production planning, puts forward a fuzzy control method based on interval valued fuzzy sets (IVFS), and gives the sensitivity analysis of the models to differing cost structures. The results states that it not only simplifies the calculating complication, but also has analysing flexibility. Then, aiming at the problems of production planning, the thesis discusses the fuzzy multi-objective programming model with fuzzy parameters for the first time, and gives its solution. At the same time, it discusses several interactive method of multi-objective optimization problem, through the exchange between decision—maker and analyst, absorbing the preference information of the decision-maker, to gain a more practicable solution. The thesis also studies the interactive fuzzy programming method of multi-objective group decision. At last, aiming at the production scheduling problems, the thesis raises the fuzzy multi-objective network method about processing plan and production schedule program with fuzzy advancing period , and it also studies the scheduling of the open shop with fuzzy due-date for the first time, and gives preliminary results.