The key to quality throughput within a warehouse, especially in a high-speed/high-volume environment, is the ability to move a carton into and out of a pick zone expeditiously.

When a warehouse control system (WCS) doesn’t process the information to divert products quickly enough, it causes cartons to be recirculated on the conveyor. This diminishes effectiveness, efficiency and quality control. Software must allow for consistent high-quality throughput, eliminating recirculation with effective communication between the WCS and the programmable logic controllers (PLC).

To achieve quality order fulfillment, the cartonization algorithm of a WCS selects the correct-sized carton for an order before the pick-and-pack process begins. The elimination of repacking is a central component in quality distribution: When the number of “touches” of the product is drastically reduced, quality control becomes lean and quantifiable.

Implementing a WCS with cartonization and zone skipping reduces the number of touches because of:

• Cartonization—the carton doesn’t have to be repacked from a picking tote into a box. Therefore, the product doesn’t have to be touched again.
• Zone skipping—the carton is only diverted to pick zones where picks will occur.

Quality pack-out
The pack-out function is a process where distribution plant floor operators add material to prevent products from sliding around in the box, verify the contents visually, insert the packing slip and tape the box shut, either manually or with an automatic taping machine. Depending on the design of the system and the technology built into the WCS, packing documents can be printed manually or automatically. As cartons are diverted down a packing lane, the packing slip is automatically printed, eliminating an operator function. This lean implementation eliminates waste at the distribution level. The operators need only match the packing slip with the carton.

WCS drives lean process improvements

• Printing and applying packing slips during shipping eliminates the need for clerks to ship product.
• Variable picking methods are available to suit any environment: batch, cluster or order.
• Order picking and cluster picking are the same thing—orders with many stock keeping units (SKUs) are picked into a shipping carton.
• Batch picking: When there are multiple, one line, one SKU orders, picks are done to a tote and are packed into individual shipping cartons or envelopes at the pack-out station. Wave planning provides management tools to facilitate the release of orders in an efficient way to combine orders and balance the flow throughout the distribution center. For example, waves may be defined by area of the warehouse, by type of product or by type of order. Wave planning allows the warehouse manager to plan picking for the day and is a quality methodology for grouping orders together for more efficient picking.

Configurability and quality at the distribution center
According to Tom Verzi, vice president of QC Software, a WCS firm based in Cincinnati, “Configurability allows users to make system changes quickly and easily to handle any physical changes in the warehouse. Many of our clients have expanded their warehouses. This could be adding a conveyor, a sorter or anything physical. A quality WCS must be configurable; no hard coding is needed to react to physical changes within the warehouse.” Configurability also allows for quick changes in how cartons are processed within the warehouse.

Emulation tools eliminate bottlenecks
Emulation tools allow for minimal live testing and help identify bottlenecks in the process. This quasi theory of constraints (TOC) is a built-in functionality in some systems that recognize the requirement of testings to provide the functionality of the system.

If problems occur during an emulation process, quality trace messaging and debugging tools allow distributors to find the problem and fix it quickly and easily.

Quality distribution is a new extension of quality manufacturing
Distribution is becoming more visible for two main reasons. First, the shift to manufacturing overseas is causing U.S. companies to store more products in distribution centers, because of the time it takes for products to arrive. Second, despite the cost efficiencies of global manufacturing, customers want their products now. The role of expedited picking, packing and shipping is an essential element in making quality manufacturing transparent.