Russell D. Meller, Lisa Thomas
University of Arkansas
Overall warehouse design is a complex process that involves both structural and operational decisions that ultimately affect the overall performance of the warehouse. Because these decisions are interrelated, determining the best design is difficult without a common platform for comparing and evaluating the numerous designs that are possible. The purpose of this project was to provide that common platform in an attempt to improve warehouse design.
This project was motivated by two CELDi projects with a member organization that designed multiple warehouses each year. In doing so, the organization considered design decisions such as warehouse shape, dock door configuration and forward area size. In each of the two CELDi projects a different tool was developed to assist the company in making specific design decisions related to their particular operating policies.
The goal of this project was to develop a generalized tool for overall warehouse design that incorporates a range of design alternatives. The CELDi Warehouse Design Tool is an Excel-based decision support tool that was developed to assist practitioners in comparing and evaluating various designs for a manual warehouse. The Tool incorporates functional flow networks that are often used to conceptualize overall warehouse design. Each functional area in the warehouse is sized to accommodate a given number of storage locations, and the flow of product from one functional area to another is translated into labor requirements using analytical models. The Tool considers pallet put-away and retrieval, as well as order picking and replenishment for case- and piece-picking operations. A generic example was developed to illustrate the functionality of the Tool and to provide detailed instructions in using it to generate designs.
Our recommendation is that practitioners utilize the Tool in the preliminary design phase of a new warehouse or in the reconfiguration of an existing warehouse, as the combination of possible design parameters results in hundreds of possible designs to consider. The Tool allows practitioners the ability to evaluate and compare many different designs that otherwise might not be considered. Various designs can be evaluated, stored and compared in terms of building size and labor hours. The preliminary design can then be further analyzed and optimized based on each organization’s objectives and cost parameters.
The Tool has not been tested on a wide variety of practitioners. However, a group of undergraduate students (divided into 4-student teams) successfully used a previous version of the Tool as part of a case-study design experience. Each team was able to quantify the advantages of a forward area, with most teams (correctly) only placing a subset of the items in the forward area. The Tool appeared to be responsible for the teams’ ability to successfully search the large solution space, which represented an improvement over the results from prior years.