| Nowadays,the inventory problem is a classical and significant issue in the Op-erations Research literature.Decision making in inventory problem is always ac-companied by uncertainty especially when dealing with demands of new products,fashion goods and other seasonal products.The uncertainty usually brings the risk of losses.Therefore,if we know how to deal with the risk of losses correctly,we can make rational policies for the inventory problem.In the classical modeling approach,an optimal inventory policy has to trade off the risk and the total expected profit with further consideration on the decision makers’ declared risk preference.In the decision-making process,the risk neutral decision makers concern more about the profit of the products.However,risk averse decision makers in the inventory problem tend to be more concerned about the risk of losses compared with profit.There-fore,in this dissertation,we study the profit and risk of the multi-item single-period inventory problem from two aspects:risk neutral and risk aversion.This dissertation mainly studies the risk-neutral and risk-averse multi-item single-period inventory problem by credibility optimization method in fuzzy en-vironment.Firstly,the risk-neutral multi-item inventory model is established,the goal of proposed model is to maximize the profit.Secondly,when the uncertain demands are mutually independent fuzzy variables,we analyze the properties of the proposed model and discuss the solution method.Furthermore,this dissertation considers profit and risk simultaneously,and establishes the risk-averse absolute semi-deviation inventory models by using the multi-objective method.Then we transform the bi-objective model into its equivalent single-onjective forms and give the model analysis by the min-max modeling idea.Subsequently,we give the cal-culating formulas of the absolute semi-deviation for the reciprocal of the demand undercommon possibility distributions.Finally,the numerical experiment for the equivalent models is given,and the results demonstrate the effectiveness of the mod-eling idea and the solution method.The major contribution of this dissertation includes the following four aspects:(i)Risk-neutral and risk-averse multi-item inventory models are built;(ii)The equiv-alent models of the expected value and the absolute semi-deviation inventory prob-lem are analyzed respectively in fuzzy environment;(iii)This dissertation discusses the properties of the uncertain demand under common fixed possibility distribu-tions and variable possibility distributions and presents the theoretical results;(iv)The numerical experiments are designed for the three classes of inventory models and the results are obtained by softwares,which illustrate the modeling ideas and demonstrate the effectiveness of the proposed optimization methods. |
