Optimizing warehouse transportation : A simulation study of racking and slotting configurations

Abstract: Background Warehouse efficiency has gained a lot of attention in the recent years where racking layout and slotting of the SKUs are essential. The efficiency can be measured in the total traveling distance that occur in the warehouse. Two of the most central racking layout and slotting policies are the fishbone layout and ABC class-based slotting. These policies offer many new advantages for the traveling distance compared to others.   Objectives The purpose of this paper is to investigate how a combination of a fishbone layout and ABC class-based slotting affects the total traveling distance relative to a traditional layout with random slotting. This will then be analyzed in order to investigate to what degree it can be implemented depending on the situation a company has.   Methods The study was carried out as a simulation study, simulating the forklift traveling distance between four different warehouse layout and slotting configurations. This simulation was done by gathering of information in the form of observations, interviews, measuring and data from the EDI system of the company. The simulation was made in excel and featured eight possible scenarios depending on different events which could occur in the warehouse. The data in the study were then analyzed through a one-way ANOVA test, Scheffe’s post hoc test and t-Tests.   Results The result of the study shows that the different events which can occur in the warehouse is affected by a change in layout and slotting configurations. With the implementation of new layout and slotting configurations it is also shown that the forklift traveling distance in the warehouse can be reduced. The result also shows that the isolation of the effects that the respective layout or slotting policies provides reduces the forklift traveling distance individually as well as a combination would do.   Conclusions The conclusion is that the Fishbone layout with ABC class-based slotting is the optimal solution considering the reduction in traveling distance in a warehouse. When considering the implementation process and the potential benefits with the configurations, a general company is recommended to consider what amount of resources they are willing to invest before they carry out the implementation.   Delimitations This paper is delimited to the total travelling distance that occur in a warehouse because of the time restriction. The study will not examine the intangible part of a warehouse which means that the WMS- system will not be addressed. The paper will not create an investment calculus for the proposed solution.