WMS meets MES

Bob Trebilcock, Editor-at-Large -- Modern Materials Handling, 11/10/2004

At many companies, manufacturing and distribution are like distant cousins. Yes, they're from the same family, but they rarely have much to do with one another.

The same holds true for warehouse management (WMS) and manufacturing execution (MES) systems, the software systems that manage warehouses, distribution centers and plants. They perform similar functions within their silos, but rarely share information.

That, however, is changing. Companies increasingly need to gather more real-time information about their operations for planning and execution purposes. That information can also be used across applications in real time to optimize manufacturing and distribution processes. WMS and MES are now meeting.

These get-togethers are happening in two different ways. In one scenario, the WMS is working hand-in-hand with the MES to manage portions of the manufacturing process. In the other scenario, the two are sharing information which allows both systems to optimize their operations now rather than wait for a supply chain planning system to react to demand.

In the first scenario, the two systems play to their strengths. An MES creates a bill of materials; schedules and manages the flow of work to and from the work cells involved in production; and captures detailed information about those processes.

Meanwhile, the WMS manages the delivery of raw materials and components to the line; tracks work-in-process between workstations; and then takes ownership of the finished product at the end of the manufacturing process.

Irista (866-447-4782) even has a term for the intersection of WMS and manufacturing functionality: "production logistics".

"It refers to the progressive steps of managing inbound transportation of raw material from suppliers to a processing facility through the delivery and consumption of that material as it is transformed into a finished good," explains Dave Adams, Irista's vice president, product development. "At the same time, you're tracking and controlling the who, what, when, where, and how through the entire process."

The consumption and transformation of the inventory during the manufacturing process is a key benefit of linking a WMS and MES, says Wes Downie, vice president, distribution systems, Foxfire Technologies (678-445-7763), a software provider of both MES and WMS systems.

"If we get a call from a customer about a finished good that has a problem, I can now click on the finished goods container and see all the raw materials and components that were pulled to make that product; what machine it was produced on; who operated the machine; and when it was produced," Downie says. "That's a level of reporting that a WMS doesn't have on its own."

In applications involving the production of unique products, like doors and windows, manufacturers are even using their WMS in place of an MES system, according to Tom Kozenski, product marketing leader for distribution at RedPrairie (877-733-7724).

"In our system, we can accept work orders directly from a host system, create a multi-level bill of materials, associate that work order with a production line, and capture the serialization of those parts, just like an MES," says Kozenski. "In a complex manufacturing environment, we can sequence parts to locations at the line. The system will also track the labor and labor costs associated with that line to produce a specific order."

The first scenario comes at the problem from the WMS perspective. There's also an advantage to manufacturers who link their manufacturing systems with the WMS in their finished goods warehouses, even if the WMS isn't used in the manufacturing process.

"A traditional WMS has a great deal of visibility into outbound orders and demand," explains Phil Walker, product marketing manager for Brooks Software (978-262-4497). "When you bring that information into an MES system in real time, a plant manager can look at his manufacturing plan and make better decisions about what to work on next, and in which facility to make a product based on what's going on in the marketplace."

That demand information will still go to a traditional planning system for longer range plans; in the meantime, the manufacturing operations can use the real time demand to optimize what's going on now.

"With shortened product life cycles, getting the right information from a WMS to make sure we're producing the right products makes the MES that much more valuable," says Walker.