WMS vs WCS vs WES
Today’s fulfillment centers might have multiple zones of manual and automation subsystems like automated storage and retrieval (AS/RS) solutions or robotic goods-to-person (GTP) systems that may have software that manages some aspects of inventory, along with storage and bin location functions.
Getting these subsystems to interoperate smoothly with WMS when it comes to real-time inventory allocation as part of order release, as well as timely replenishment of SKUs needing by multiple picking systems, is changing the functional needs in the WMS market. Metering the flow of goods around order release is also part of the value proposition for warehouse execution system (WES) software, a category of software that sits between the automation and WMS.
What is a Warehouse Execution System?
A warehouse execution system, or WES, is a software solution that can direct all of the processes that take place inside a distribution center. The WES works in real-time to organize, sequence and synchronize all warehouse resources: material handling equipment, devices, and employees. This reactive solution moves orders in a continuous flow. If a condition changes in one part of the process, the system will reprioritize work to expedite fulfillment.
WES vs. WMS vs. WCS
In recent years, the material handling industry has categorized the various software platforms for operating distribution operations using the terms Warehouse Management System (WMS), Warehouse Execution System (WES), Warehouse Control System (WCS) and machine control systems. These terms have arisen to distinguish key features and operating paradigms between the contributions of various software systems.
In addition to these systems, there are labor management systems, order management systems, material and resource planning systems, transportation management systems and other systems that distribution centers may deploy to manage the entire operation.
In an ideal distribution world, one would prefer a single software system that could provide all of the requirements for driving an operation. However, no such platform currently exists.
The WES sits between the WMS and the work resources necessary to accomplish the work plan, and it directs both people and machinery in real time as to execute the plan. The biggest distinction between the WMS, the WES and the WCS is the decision-making processes themselves and their timeliness.
The WMS creates work plans and the time to compute a work plan is not critical to the operation. Work can be planned hours before the work is to be executed. The WCS, however, is very critical to time or the timing of direction to control the material handling equipment, which requires real-time direction to operate.
While the WCS is capable of making real-time decisions within its silo of machinery, the operational direction is provided by another system. That leaves the WCS with little operational decision capability and relegates it to execution of a plan.
Traditional WMS computing architecture is not based on making real-time decisions. To effectively make real-time decisions, the system of choice (WMS, WES, WCS) needs to know the status of all of the required resources at the decision time.
Some WMS providers continue to improve the timeliness of decision making, at times referring to “near real-time” operations. However, until they achieve real-time operation across all work resources, the distinction between a WES and WMS will remain.