Fuzzy multi-objective evaluating method for hybrid assembly line design

Hybrid assembly line referred to a kind of assembly line with more than one operation mode. Multi-objective optimization is a more practical method for hybrid assembly tine design optimization because several design objectives could included in optimization process, such as cost, workload balance, reconfigurability and so on. Multi-objective optimization for assembly line design is an active research field in recent years. The Pareto-based optimization procedures for hybrid assembly line design usually contain two steps. The Pareto optimal frontier is achieved firstly, then the final best solution must be chosen by a decision maker with his experiments from the Pareto optimal frontier. It could lead to more complexity to make a decision with the number of optimization objectives is getting larger. So, how to evaluate the solutions on the Pareto optimal frontier is a problem that related to design quality and efficiency of hybrid assembly line. This paper presents an Fuzzy multi-objects evaluating method for hybrid assembly line design. Firstly the mathematical model is constructed for fuzzy multi-objectives evaluating problems. Then several definitions on fuzzy optimization are used to describe the relationship between the Pareto frontier evaluating and fuzzy multi-objectives decision making. Thirdly the procedures for evaluating the solutions on the Pareto optimization frontier are proposed. The method is different from other evaluating methods in two aspects. One of them is that it maps the problem of design solutions evaluating of hybrid assembly line design with fuzzy multi-objective decision making problem. The other one is that a new effective index is defined for evaluating multi-objective solutions on the Pareto optimization frontier. Finally, a numerical example study is presented. The methods is capable of tackling hybrid assembly line design optimization problem more rationally