MULTI-ITEM MULTI-PERIOD INVENTORY CONTROL

Abstract

in inventory problem i. a problem of making optimal decisions with respect to an inventory system or in other words itis a problem concerned with decisions which minimise the total cost of an inventory system. If cost of one para- meter is increased/decreased,. the connected cost of another parameter may decrease/increase. Therefore, we have to endeavour to minimise the sum cost. We can also say that an inventory problem is a 'problem of making optimal decisions with respect to various inventory costs. A mathematical model for multi-item inventory control has been developed in Chapter II. A practical example has bwn .discussed for the efficient and speedy repair of Truck 1 Tonne Nissan vehicle used in the Army. The optimal inven-tory that must be maintained for this (of course with the constraint that a certain level of user satisfaction is maintained) has been found with the help of a computer. Reliability based inventory control problems,formu-lated by considering the failure rates of the components, have been developed in Chapter III. The number of spares required to be maintained are found out by maximising the reliability of the system in which these components are used. The identical components are bunched together into component groups. In this chapters the mathamatical model developed has been transformed intoaa zero-one programming iii problem which has a special structure. By exploiting the special structure, the problem is solved by a partial -,enumeration technique. This method requires less computa . tional time than earlier methods. The drawback of the methodf however,lies in the fact that the number of variables in this type of formulation is larger than in other methods, n algorithm for this method has been discussed in this chapter alongwith a practical example. Chapter IV deals with the formulation of a multi-item multi- period inventory control problem and developing the optimality conditions for a No fixedi-cost of ordering' and apositive fixed cost of ordering: