Warehouse management systems are large, complex, data intensive applications that require adequate resources and ongoing data management. Their functions include three major processes - directed picking, directed replenishment and directed putaway. The benefits are reduced inventory, reduced labor costs, increased storage capacities, increased customer service and increased inventory accuracy. These are functions that can benefit nearly any warehouse, large or small, but management must determine whether or not a warehouse management system is beneficial enough to justify what it takes to run.
The truth is that a WMS requires substantial setup. Each items characteristics must be defined, along with its location. Exact dimensis and weights must be provided to the management system in order for it to determine best case storage and picking facilitation. Whether an item is stackable, detailed dimension measurements, hazard classifications, and a ton of other information must be input into the WMS before it can function properly. Specific logic must be assigned to all of the various combinations of items including the order, quantity and location information that will determine how the software views that item. Sequences and locations may be determined by location sequence, zone logic, a fixed location, a random location, first-in-first-out, or a fewest locations scenario. Pick-to-clear, reserved locations, nearest location, maximize cube, consolidation and lot sequence are also ways of determining how storage, picking and replenishment will occur. It is not uncommon to combine two or more of these methods, but that logic has to be provided and programmed into the WMS system for it to function properly.
There are numerous other considerations. For example, how will picking be organized - by wave, by batch or by zone? How will counting cycles be coordinated and which method of automated data collection will be utilized? For WMS to work it must be able to collect data from radio frequency, bar code scanners, or some other means. It must be integrated with automated material handling equipment and, if the receiving process is to be automated, advanced shipment notifications must be electronically available. Cycle counting, cross docking, slotting, yard management, and labor tracking are all additional functions that can be a part of the WMS system if those functions are needed at the particular warehouse and will be utilized enough to justify the cost of their installation.
The methods of accounting must be determined in advance as well. Will the system use activity based costing and billing and will it integrate with existing accounting and ERP systems. There are dozens of other modules that are being added to WMS packages, including full financial, light manufacturing, transportation management, purchasing and sales order management, just to name a few.
All things considered, it becomes clear that implementing a WMS is not a walk in the park, but a complex process that must be carefully thought out in advance. Once a system is installed, there is little room for navigation. A business must operate within the predetermined parameters that have been installed, since WMS systems are data dependent and restrictive by design. When thousands of dollars and countless hours of labor are at stake, the design and implementation need to be thoroughly thought out before the final steps and implementation are taken.