Comparison of Expected Distances in Traditional and Non-Traditional Layouts

The performance of a unit-load warehouse depends on numerous parameters such as storage area, layout, aisle configuration, width-to-depth ratio, the number and locations of dock doors, storage policy, etc. These parameters typically relate to the layout configuration, which can be either traditional (rectangle-shaped) or non-traditional (contour-line-shaped). In this paper, we analyze the performance of rectangle-shaped and contour-line-shaped storage areas within a unit-load warehouse having multiple dock doors. Expected distances traveled in rectangle-shaped storage areas are compared with expected distances in their counterpart contour-line-based storage areas when an ABC class-based storage policy is used to assign unit-loads. For a single product class, the expected-distance for a rectangle-shaped storage area is at most 6.07% greater than it is for the corresponding contour-line-shaped storage area. Depending on the skewness of the ABC curve or storage areas for multiple classes, the expected distance for rectangle-shaped storage areas can be no more than 0.59% greater than it is for the corresponding contour-line shaped storage areas when multiple dock doors are distributed with a specified distance between them.