St. Onge Company Links Supply Chain Blog
Strengthening your supply chain one link at a time.

Meet the Maestro: Warehouse Execution Systems (WES)

Typically, we see multiple types of warehouse automation in facilities, such as automated storage and retrieval systems, high-speed sorters, conveyors, pick to light, autonomous vehicles, and robot picking/packing. The goal of today’s discussion is to focus on software deployment strategies that allow for the best utilization of these technologies.

Behind each of these warehouse automated systems, there are sophisticated pieces of software designed to allow these machines to operate correctly and accurately. Needless to say, these systems are critical. Warehouse automation and software vendors often tout their benefits as if they will exist in a vacuum. This is not true. Instead, how well these systems are synchronized often determines whether or not the implementation is successful.

The challenge of realizing these benefits lies in the coordination of the capabilities of multiple systems. In facilities where multiple pieces of warehouse automation are in place, there is a need to coordinate tasks, balance workloads, and monitor performance so that these systems are working in perfect harmony. To that end, a Warehouse Execution System (WES) has proven to be especially effective when properly deployed – hence the “maestro” reference.

Sonato: The Role of a WES

There is confusion in the market regarding the purpose of a WES and how it differs from Warehouse Control Systems (WCS) and Warehouse Management Systems (WMS). Although they have been around for over ten years, WES is newer in terms of naming terminology, but not in terms of technology. In an industry that does not lack acronyms, adding WES to the alphabet soup has understandably created confusion.

Modern WES evolved from WCS software originally designed to control material handling equipment such as conveyors and sorters. A WES is a more productized WCS. Over the years, WESs have slowly added more and more WMS functionality. The overlap of WMS functionality in a WES has led to confusion.

There are key differences to keep in mind:

  • A WMS is primarily a tactical tool used to support DC management and staff
  • On the other hand, a WES is primarily an execution tool that can more easily adapt and respond to changing work environments

As a tactical tool, a WMS is extremely efficient at planning warehouse operations and organizing and directing tasks. The execution of tasks – particularly where multiple pieces of warehouse automation must work in harmony – is where a WES provides an advantage. This execution ability is part of the DNA of a WES considering its growth from a WCS. As a result, a WES tends to have a bottom-up approach to warehouse operations – starting with the warehouse automation – as opposed to a top-down design that you find in WMS.

Minuet: WES Integration

A WES can also manage and orchestrate multiple work streams and coordinate tasks across multiple systems. A WES-centered integration approach streamlines integration by positioning it between the WMS and warehouse automation. In fact, several best-of-breed WESs contain native WCS support that allow direct connection to programmable logic controllers, meaning they can directly control the warehouse automation without the need for WCS software.

Positioning the WES between the WMS and automation allows automation integration regardless of WMS (whether it is custom/legacy or lower tier) and avoids costly upgrades. And because there is some overlap of functionality, this approach can offset “yet to be deployed” WMS functionality.

Because the WES is centrally located, it is in a unique position to collect data in real time from warehouse automation. All of this data has tremendous value when combined with business and artificial intelligence tools. The ultimate goal is to get to a point where this information can provide a windshield (forward) view of operations rather than a rear mirror view found in standard warehouse reports and dashboards.

This approach can also be seamless to most users, eliminating the need for a learning curve by taking advantage of a black box integration. With a black box integration, the WES receives and responds to direction from the WMS only. Users continue to work directly in the WMS to execute tasks. This seamless integration, where applicable, reduces the learning curve for most users. Only advanced IT users will have the ability to access the WES for troubleshooting or other advanced tasks.


Good orchestra conductors are good leaders. They wave their batons and blend various orchestra components into one cohesive unit aligned for the common goal. They have to be good analyzers of the score/music (objective), musicians (warehouse automation), and the sound being produced (data).

Keeping your facility in time and together is just the starting point. Most importantly, the maestro serves as a messenger for the composer. No matter how well the music is composed, it will be out of tune without a maestro to transparently convey the music to the musicians.
–Howard Turner, St. Onge Company

Enter your email to subscribe to "Links":


St. Onge Company is Proud to Have Been Ranked Among the Highest-Scoring Businesses on Inc. Magazine’s Annual List of Best Workplaces for 2023

We have been named to Inc. Magazine’s annual Best Workplaces list! Featured in the May/June 2023 issue, the list is the result of a comprehensive measurement of American companies that have excelled in creating exceptional workplaces and company culture, whether operating in a physical or a virtual facility.

From thousands of entries, we are one of only 591 companies honored.

Click here to see our listing!