In today’s busy distribution centers, high-speed order fulfillment and tight inventory controls are supported by advanced technologies and creatively designed product storage structures. One of these storage solutions is the pick module. Here’s how to select one.
Pick modules are large and often complex structures designed to facilitate storage and order fulfillment of bulk items and single picks, which are referred to as “eaches.” It is this fundamental characteristic of the pick module, the ability to handle a broad diversity of products and order types, that makes it such a unique and integral part of the distribution center. Pick modules are constructed from the most basic pallet racking components, namely the uprights and beams common to just about every bulk storage and material handling system. A variety of subcomponents are then integrated into the basic rack structure, primarily for the purpose of facilitating product movement and inventory control.
While there is no such thing as a standard pick module (they are generally customized for a particular facility or application) there are some common traits between them. A typical pick module today is a multi-level structure that takes full advantage of the vast cubic space resulting from the high ceilings common in most distribution facilities. Pick modules may contain hundreds or even thousands of SKUs. Larger distribution centers often have multiple pick modules under one roof, each dedicated to particular product types or to a common characteristic of a product set, such as its propensity to be ordered (e.g., fast movers versus slow movers).
The main components that make up a pick module include racking material, structural subcomponents and picking subcomponent.
Although commonly overlooked or often considered somewhat inconsequential, the racking material is the backbone of the pick module system. With a thoughtfully designed and expertly fabricated rack structure at its heart, a pick module will provide a consistently safe, versatile, efficient, and effective means of distribution for a wide and ever-changing array of SKUs.
Two of the most important factors for consideration when selecting a rack supplier for a pick module are quality of product and innovation of design. Not all rack suppliers are created equal. Pick module design, installation and support are specialized talents. Beware of a low up-front price as it often does not equate to overall cost effectiveness. A more creative and versatile design may cost more on the front end, but can save time, money and headaches in the long run as the operation matures, components wear, and material handling demands shift.
As for quality, look for a supplier with many years experience in the design and fabrication of pick modules. Ask to see product samples and arrange for tours of other distribution centers that use the brand and type of rack being considered for purchase. The condition of a working pick module system, along with feedback from the facility staff, will help guide your decision and may even provide new ideas and options you hadn’t previously considered. Finally, your rack supplier should be RMI (Rack Manufacturer’s Institute) compliant in their designs, and have an internal quality system such as ISO in place at their manufacturing facilities to help ensure safety, consistency and performance.
Since most pick modules are multilevel, stairs and flooring are also essential items in the design. A typical pick module flooring system is usually comprised of beams spanning between rack uprights, metal decking and a wood wearing surface. Additional items that need to be considered are hand rails, toe boards, lighting (including emergency lighting and exit lighting), and sprinkler systems.
With an infinite number of configurations and loading combinations available you’ll need an integrator with facility design and engineering expertise to develop a pick module system—especially if you’ll need building permits. Local municipalities typically have different requirements on other specifics such as the number of exits required, the height and depth of each step within a set of stairs, the height of handrail in the stairs and around openings, the number of exit signs required, and much more.
The picking-related components within the rack system are what makes the necessary activities achievable. A few different types of picking subcomponents are:
- Case flow (a.k.a carton flow) – Typically a gravity fed, first-in/first-out roller system that allows pickers to move one box or case vs. a full pallet. Also used to pick eaches from open cartons.
- Pallet flow – Another first-in/first-out gravity fed design using rollers that allows pickers to use a full pallet as the base for their picking operations with another full pallet waiting behind the current one for immediate replenishment.
- Reserve rack – Provides additional product storage to support uninterrupted picking operations.
- Push-Back rack – A first-in/last-out dense rack system often used in the design of reserve rack.
- Pallet return lanes – A feature designed within the pick module that allows for the safe and easy removal of empty pallets for easy pick up in lift truck aisles.
- Conveyor – A mechanized belt or roller system for efficient transport of products from storage locations to the packaging and shipping areas, and from receiving or inspection areas back to storage areas as with product returns. Often also used to safely transport debris, empty containers and other non-product elements that require removal from picking areas.
A large pick module system is often the best choice for a high-volume, high throughput distribution center operation. But even most simple picking operations can benefit form the versatility and efficiencies created by installing a pick module. All in all, there are many factors and options to consider when determining whether a pick module is the right solution for a particular application; the resulting benefits from a properly designed, installed, and maintained pick module system can be significant.
Vincent DePaola is manager of retail sales and marketing for Naperville, IL-based material handling provider Interlake Material Handling.