WAREHOUSE DESIGN

WAREHOUSE DESIGN
It is clear that the design of a warehouse system concerns a large number of interrelated decision. We attempt to structure the decision in a hierarchical framework. In addition we discuss a number of performance criteria that serve to evaluate alternative designs.

WAREHOUSE DESIGN METHODS
A design process typically runs through a number of consecutive phases, data acquisition, functional specification, technical specificaction, selection of means and equipment, layout, and selection of planning and control policies. Alternatively, these decision may be situated at a strategic, tactical or operational level. The basic storage system is a strategic one where the dimensioning of these system and determination of a layout are tactical decision. Detailed control policies typically belong to the operational level.

WAREHOUSING MODEL
An overview of model and algorithms proposed in the literature for warehousing design, planning and control. In doing so, we follow the classification of problem at a strategic tactical or operational level at each level we further discuss papers within problem.

WAREHOUSE DESIGN PROBLEM: Strategic Level
At the strategic level, two problem clusters have been identified on dealing with the selection of system and equipment based on technical capabilities and the second one dealing with the design of the process flow and the selection of warehouse system based on economic considerations.

According to Keserla and Peters compare the performance of a standard automated storage using analytical expressions and simulation. Dunkin develops a design and algorithm for warehouse containing total-sized load. A very interesting study has been published by Sharp etal. The number of publications concerning design problems on a strategic level appear to be limited despite the fact that at this level the most far-reaching decision are made.

Warehouse Design Problem: Tactical Level
At the tactical level, most decision concern the size of the organization. The publication in this section are classified into storage system type.
Determine the size and layout of conventional warehouse has been the topic of several publications. Berry and Bassan et al analyze the layout of a conventional warehouse. They provide an optimization model to determine the optimal dimension of the layout, in order to minimize handling distance, handling time, space utilization or cost.

Warehouse Design Problem: Operational Level
At the operational level, most decision concern the assignment of task to, and the scheduling and control of people and equipment. The publication in this subsection are problem according to list of topics discuss.
1. Batching
According to Elsayed and Sterm test 24 batching algorithms with the aid of simulation. Rosenwein analyze order maximum throughout in a conventional warehouse with batch by means of a simulation study.
2. Storage Policies
Geotschalckx and Ratliff evaluate storage policies for block storage through an analytical study. Marsh has been working on the same problem but evaluates two alternative policies. Van den Berg and sharp propose a procedure base on linear programming for product allocation in a warehouse consisting of a forward and reserve area to minimize the costs of order picking and replenishment.
3. Routing and Sequencing
Geider and Heeremans analyze routing in a conventional warehouse. Goetschalckx and Ratliff Hall and De Koster and Vander poor determine analytical expressions to evaluate the routing in a conventional warehouse.
4. Dwell Point Selection
Egbelu presents an algorithm for the dwell point selection, using linear programming, also Egbelu and Wu evaluate several dwell point policies with the aid of simulation.
5. Storing and Sequencing
Graves et al evaluate the impact of sequencing and class-based storage policies on warehouse performance, base on analytical expression for continuous racks and numerical procedures for discrete system.
6. Miscellaneous
Sarker and Babu review the literature concerning the operational control of AR/RS’s van den Beg analyzes a number of operational control problem. Forward reserve allocation, class based storage, routing in carousels and AS/RS’s and well point selection.