Class Based Storage with Mixed Integer Linear Programming Approach for Hazardous Materials Storage

Abstract

The paper presents storage location assignment problem using a new mixed integer linear programming approach for class based storage assignment in hazardous materials storage. Class-based storage strategy is widely used in practical division of all stored items into a number of classes according to their turnover. Material safety data sheets are used for determining the special needs of storing criteria. Storage location assignment problem problem is solved using a new proposed mixed integer linear programming model. Main objective of our approach is directed to a class of items with higher turnover allocated to region closer to the warehouse depot. As a result, materials are assigned onto dedicated storage areas while considering the storage constraints of item-to-location and item-to-item in chemical warehouse. Moreover, the item-to-location constraints mean that the item has specified characteristics and needs to be stored into specified racks. For item-to-item constraints, some items should not be stored close to each other. These constraints confine the storage assignment strategy environment. Mixed integer linear model is solved using the Branch and Bound algorithm to minimize travelling distance inside the warehouse. The results indicated that the proposed approach improved the picking efficiency significantly and decreased prevalence of all unexpected situations such as death due to danger, injury, and trouble.