Warehouse execution systems (WES) evolve

Warehouse execution system (WES) software has emerged as a means for automated distribution centers (DC) to fulfill a high-velocity order mix while hitting tight delivery requirements.

A core WES function that helps with this challenge is known as “waveless” order releasing in which orders are dropped to the floor on a continuous basis, letting the WES dynamically orchestrate machine, labor and inventory resources against order requirements. This differs from how most warehouse management system (WMS) solutions have traditionally processed orders in pre-planned chunks of work known as “waves.”

However, WES is more than a niche solution for waveless. As vendors point out, WES can integrate with transportation updates to keep execution in balance with dock activity and logistics, while WES is also evolving in terms of analytics. In short, it’s not just a one-trick pony, but an increasingly important layer of software that blends key aspects from the WMS level with the type of machine awareness that warehouse control system (WCS) software traditionally has governed.

Roger Counihan, vice president of sales with Fortna, a professional services and WES provider, agrees WES has attracted interest via its ability to more efficiently orchestrate order fulfillment within a DC. Without WES and reliance on more traditional waves that group static blocks of work together, he notes, there tends to be a sine wave pattern to efficiencies, with good efficiency at the start of a wave, but a falloff as the wave winds down. To compensate, operations often need to throw more automated equipment or people at fulfillment to get the throughput they need.

“That is a big part of what’s driving people to WES,” says Counihan. “It allows them to be more efficient with less investment.”

What tends to be forgotten in this focus on order releasing under WES, is that an effective WES is also taking in updates from transportation management system (TMS) solutions or electronic data interchange (EDI), and dynamically adjusting the pace of work and priorities, based on changes in arrival times or dock door assignments.

Counihan says: “We look at our WES as enabling pull-driven flow, and as part of that, it is looking at the outbound picture and assessing, ‘how do I maximize what is flowing out of the building so that orders get to customers on time and accurately?’”

Similarly, on the inbound side, an effective WES needs to be able to integrate with data from enterprise resource planning (ERP) systems or EDI updates, in particular advance shipment notices (ASNs), to optimize the receiving and put away process, and look for opportunities to cross-dock inventory to fill customer orders. “On the inbound side [WES] is absolutely looking at when is [receiving] work and incoming product going to be available, and ideally, when can you cross dock in one simple move,” says Counihan.

The WES concept

There are different vendor approaches to WES, and different ways vendors entered the market. Some of the leading WES providers have a heritage as warehouse integrators who developed WCS and evolved those into WES solutions. A few companies that began with WES software have been purchased by large warehouse automation providers, while some WMS and supply chain execution software suite providers have come out with WES capabilities.

While changes to outbound shipments should be passed on to any WES or WMS solution, it’s also important for WES to have effective integration to inbound shipments, says Ryan Sheehan, CEO and co-founder of Invata Intralogistics, a WES provider. “Integration to transportation data is also important on the inbound side, where a WES’s optimization algorithms start creating flow for the overall facility. Visibility into incoming shipments and yard management is becoming critical to what we are doing,” says Sheehan.

Invata believes in providing integrated solutions, rather that niche systems, says Sheehan, so it has some parcel manifesting and TMS functions it offers, or it can integrate WES with whatever TMS a user company might have. “Much of our development is around deep integration to the transportation management side to be able to make decisions based on the ship methods, service levels and the overall cost to get that unit delivered to the customer on the promise date,” he says.

WES differs from the more pre-planned or batch approach of most WMSs, explains Ryan. “The WES wants to be looking at things very deterministically on a sub-second basis and cranking complex optimization out,” he says. “It is looking across inventory, the material handling equipment and all of the considerations on the outbound side to meet the customer promise dates.”

WMS vendors who’ve developed WES capabilities point out that integration to TMS and yard schedules is nothing new for supply chain execution software vendors with integrated WMS, TMS and yard management system (YMS) solutions.

“There is a real need to understand everything affecting the edge of a DC operation, whether that is what is happening at dock doors or in the yard, and above that, the overall logistics flow from port or supplier to DCs for receiving,” says Sean Elliott, Chief Technology Officer for HighJump Software, a supply chain execution system vendor whose WMS has what it calls “automation aware” WES features. “On the outbound side, the DC’s systems need an accurate understanding of what the pickup and arrival times will be. This knowledge is absolutely critical to more flexibly managing resources and work.”

There are multiple ways to get logistics updates into a WES/WMS, says Elliott. With HighJump’s customers, there are TMS and YMS schedules and updates, and it’s also possible to integrate with carrier systems or EDI data. HighJump also has a module for linking to telematics updates from carriers. By integrating logistics updates to WES, the solution can re-optimize assigned tasks or resources.

“If we know that a truck is held up in transit and it’s going be another hour or two hours before it arrives, the optimization algorithm [in the WES function] is immediately going to account for that,” says Elliott. “The reality is that just like warehousing operation dynamics change on a regular basis, so do transportation dynamics.”

Overall flow

Dan Gilmore, chief marketing officer at Softeon, a supply chain software vendor whose WMS has WES capabilities, agrees it is important to link WES with the latest transportation updates so that the WES logic can adjust the flow of work. One key benefit from WES, he adds, is how it supports pull-driven work that hits customer service levels, while looking for opportunities for efficiencies from pick density, especially earlier in a shift.

“As the day proceeds, more and more of it starts to become a factor of service commitments, and making sure the parcels that are supposed to get on the truck make it there on time to meet delivery commitments,” says Gilmore. “I think now [with WES] we’ve got a vision for warehousing that looks more lean-oriented and pull-driven than the systems of the past.”

Gilmore also believes a WMS with WES capabilities is an apt solution for omni-channel DCs that want to process some orders in waves, but others under waveless. While waveless can work well with e-commerce orders or other small, parcel-sized orders that can draw on a large order pool to find pick efficiencies, processing work in waves remains effective for more traditional business-to-business orders shipped on pallets on specific trucks that might entail a preferred loading sequence, Gilmore says.

Under either a waveless or waved methodology, says Gilmore, WES is going to require less manual planning and intervention than traditional WMS because WES uses its visibility into throughput and resource availability to make decisions. “You want a system that is automatically reacting—not one that takes all kinds of manual processes and intervention,” he says.

The whole notion of an “in the four walls” system is becoming outdated under digital supply chain initiatives that involve systems with WES capability, says Scott Deutsch, Americas president for Ehrhardt Partner Group (EPG), a vendor of supply chain software that includes WES functionality. “A warehouse execution system takes in so many digital touchpoints, that the four walls of a DC don’t exist figuratively any longer,” Deutsch says. “WES capability is all about being able to deal with keeping up with a digital supply chain.”

For example, says Deutsch, if a carrier truck gets stuck in traffic, telematics on the truck and real-time integration to carrier updates can be leveraged by WES capabilities to reshuffle work, reassign workers, or make other adjustments, much like systems used in airports today can reassign a gate to a different flight if another flight is delayed. “If a DC gets a digital communication that a truck is going to be two hours late, [WES] can do some planning around that,” he says. “Supply chain execution systems in the digital age now are able to grab and apply best practices from other industries.”

Analytics advance

WES solutions also continue to expand their analytics capabilities. While reports and dashboards are part of most WMS solutions, what makes today’s analytics different is that they can be constantly refreshed with current data, says Deutsch. “The downfall of dashboards are they tend to be static—performance at a moment in time in the past,” he says. “Now with Cloud analytics, a dynamic view of data and performance is taking hold.”

HighJump’s Elliott sees a similar trend for WMS/WES analytics, fed by both traditional WMS data, and real-time status of both machinery and other resource activity from WES. “We call it operational intelligence,” he says. “It sits on top of traditional data sets as well as automation and robotics data to provide a total picture. The second thing about [operational intelligence] is that it interacts pretty heavily with our labor solution.”

The need for better DC analytics and the multiple systems in use within DCs is also giving rise to some new analytics specialists. One of these is CognitOps, which offers a Cloud-based platform that uses data from systems such as WMS, WES and WCS to make predictions and provide decision insights for managers.

Alex Ramirez, co-founder of CognitOps, says the CognitOps platform takes in data from these multiple systems to provide insights on factors including labor optimization; how to eliminate bottlenecks and idle time; how to stage inventory in the DC; and how to harmonize order release between WMS and WES. “Being able to bring in that data to say, this is how you should use your equipment, position inventory, release orders and balance your staff—across all the silos—are the fundamental questions we are answering with our platform,” he says.

Some WES solutions use simulation for tactical decision support. Softeon, for instance, developed simulation for insights into longer-term process improvements in a DC, but found that same technology could be leveraged to plan for the next day, shift or to prepare to execute on a promotion, says Gilmore.

Such capabilities make WES more than a narrow engine for waveless, and add to the total benefit potential of the solution category. As Gilmore concludes: “I think [WES] will be an eye opener for the industry in that there is still so much potential to take costs out of the DC by maximizing flow, by maximizing resources, eliminating lull time and using that drum beat derived from customer shipment commitments to pace the overall work in the DC.” 

How WES interacts with mobile robots
Warehouse execution system (WES) solutions can either directly control or orchestrate the activity of automated materials handling systems, either traditional automation like conveyors or the new kid on the block: autonomous mobile robots (AMRs). That raises the issue of the relationship between WES and AMRs—how do the two systems typically interact, and how does the integration work?

According to WES providers, the integration to the software that controls AMRs is much like integration to other automation systems, which may have some inventory under their control, like an automated storage and retrieval system (AS/RS). Just like WES can coordinate with an AS/RS or shuttle, WES can be used to coordinate order requirements or other factors like inventory replenishment with an AMR platform, says Sean Elliott, chief technology officer for HighJump Software, which offers a warehouse management system (WMS) with WES capabilities.

Initially, explains Elliott, the integration between WES and robotics has tended to be a more streamlined exchange of order requirements coming down from WES (or a WMS with WES functionality) to the robotics platform, and the robotics software sending back data on completed tasks and inventory moves/changes, explains Elliott. This is more of a “black box” style of integration, in that WES and the robotics software will exchange data and coordinate around material flow, but the WES isn’t controlling each robot directly, or governing the positioning of inventory within the robotic zone of the warehouse.

“We’ve been very impressed with the robotics space and have good relationships with a variety of vendors,” says Elliott. “Today what we see is mostly a black-box style integration, in large part because one of the big value propositions of robotics is ease of implementation and rapid return on investment.”

However, says Elliott, the link between WES and robotics platforms could evolve into a tighter relationship in which an AMR platform would still control the robots, but the WES would have added more detailed visibility into what the robot resources are doing. This more bi-directional, real-time style of integration between WES and robotics could allow for better coordination around the allocation of human labor or other resource decisions, says Elliott. “I think there is a lot of value that could be driven by a tighter coupling and more data sharing between the two universes,” he says.

WES solutions must have effective integration mechanisms with multiple types of automated materials handling systems, with robotics including goods-to-person mobile robots or collaborative picking arms being no exception, says Stuart Dunn, product manager for customer service, software and controls for Swisslog.

Since Swisslog offers a WES solution called SynQ as well as various robotics solutions, Dunn says that WES can integrate with most any type of system, but has tight, native integration with Swisslog robotics solutions such as its good-to-person robots that bring goods on rolling shelves to a light-driven pick station, or its collaborative picking arms.

The advantage of having a common solution for WES and robotics, says Dunn, is that rather than simply exchanging data between key systems, the user company has one cohesive system to manage and improve on order fulfillment. “It allows you to have one system for visibility and for continuous improvement of the operation,” says Dunn.