Three Ways to Improve Order Fulfillment

Feb. 15, 2013
Labor, time and space savings add up to significant financial savings if you slot, package and pick correctly.
Order fulfillment is often reported to consume more than 60% of the total direct labor associated with warehouse operation.  Consequently, the warehouse picking area usually offers the best opportunities for savings through use of optimization methods.  This article focuses on three of those methods. 

Slotting Optimization

Slotting is the process of determining where items should be placed in the picking area so that the popular items are stored close together and in close proximity to the starting point of picking so as to minimize walking time.  Slotting is often painful since it requires substantial labor to relocate items.  Furthermore, picking often must stop while items are being relocated. 

A naïve slotting approach would be to simply sort the items by popularity and place them on contiguous picking bays close to the start of picking.  The problem with this approach is that the popular zone of the picking area may get congested and pickers will be tripping over each other.  A better approach would be to “stripe” the popular items on shelves located at ergonomically beneficial heights.  This approach would lengthen the popular picking area but would also reduce congestion, improve picking speed and reduce worker fatigue.

Another important consideration in slotting relates to item size, weight and durability.  Fragile items should be picked last and placed on top of durable, heavier items already picked.   Similarly, better packing density is generally achieved when larger items are picked before smaller items that can be packed around the larger items.  A good slotting algorithm will take all of these factors into consideration when assigning slots to products.

Box Selection Optimization

Picking an optimal (fewest) set of boxes from a set of available boxes, and then picking, packing and shipping an order are challenging procedures and greatly influence shipping costs. Before a solution can be derived, the cube (dimensions) of the picked items must be known.  Devices that automatically measure the weight and X, Y and Z lengths of a rectangular prism that will exactly contain an item can be purchased from several sources. Using this data can help determine the smallest set of boxes needed to minimize wasted space in those boxes.