Inventory Research Under The Uncertainty Circumstance

In 1965,the conception of the fuzzy sets was put forward by Zadeh,and this uncertainty wascalled as fuzziness.Since the middle of last 90s,fuzzy sets was extensively applied in classical inven-tory theory,then'fuzzy inventory problem'was brought.Mear last years,fuzzy sets was applied invarious field by some researchers.In 2004,the credibility theory is completed as one of the math-ematic branches in mathematic field to give the axiomatic foundation of fuzzy theory.In this pa-per,'fuzzy inventory problem'that the popular idea was further studied with credibility theory.Firstly,the reordering newsboy problem(the classical inventory management model) under un-certainty condition was studied,based on the existed insu?cient modeling methods and limitedfields,the reordering newsboy problem consisted by two or multiple fuzzy parameters,stochastic andfuzzy paramter.These models of above problem were respectively built in fuzzy chance-constraintprogramming.The model of two fuzzy parameters was converted to certain model by the method ofcrisp equivalents,and the problem can be solved by traditional method;to more complicated modelwith multi-fuzzy parameters,the optimal ordering and optimal reordering were got by the hybridintelligent algorithm which combined by fuzzy simulation,NN and GA;the model with both stochas-tic and fuzzy parameters,the optimal value was got by the hybrid intelligent algorithm consistedof fuzzy and stochastic simulation,NN and GA.Finally,an example was given to explain the modeland algorithm's availability and practically.Secondly,stochastic two-warehouse inventory and fuzzy two-warehouse inventory model werestudied respectively.To stochastic inventory problem,the inventory model of ordering point wasput forward,with the assumption of the stochastic arrived time of goods and the lowest total costwas arrived by computing the optimal ordering point.To fuzzy two-warehouse inventory,the fuzzyexpected value model and fuzzy chance-constraint model were found using credibility theory,withtwo fuzzy parameters,demand rate and good's arrived time,and the optimal ordering point andlowest cost were got by the hybrid intelligent algorithm consisted of fuzzy simulation,NN andGA.Finally,an example was given to explain the model's feasibility and rationality.This paper not only a?ord adaptable model and algorithm under the uncertainty circumstanceto analysis and solve the practical problem,but also enrich the uncertain programming applicationresearch in inventory problem.