The criterion for selecting a manufacturing execution system has just changed. It used to be that if a company needed an application to schedule production, trace work in progress, or manage quality, the buying decision was based purely on software functions and price. Today, however, there's a new dimension that determines which MES software will take center stage: ERP alliances.

"We would not have selected a vendor that didn't have a relationship with SAP," says George Chappelle, CIO of Sara Lee Corp.

The reason? Pressure. External factors ranging from regulatory compliance, to global competition, to increasing customer demands are putting pressure on manufacturers to integrate internal operations so that everything runs like clockwork.

Sara Lee is under pressure from the FDA to implement a robust traceability system that can track materials and ingredients in case of a recall, for example. "In the food industry, traceability requirements are stringent today, and they'll be more stringent in the next three to five years," Chappelle says.

So, if Sara Lee's SAP ERP system is ordering raw materials, and its MES system, which is Siemens AG's SIMATIC IT, is consuming the materials, naturally the two must interface so that when something changes in one system, it is automatically reflected in the other. But these systems use data in very different ways. ERP is transactional; MES, on the other hand, works in real time. Aligning the two disparate systems to seamlessly share data in a global landscape can be a challenge. And Chappelle, like many CIOs, can't afford to have staffers spending valuable time doing the nuts-and-bolts integration work.

That's why, when Chappelle went searching for an MES system, he made at least one thing crystal-clear: "Our criterion was that the [MES and ERP] systems have technology integration," he says. And because Sara Lee already had SAP installed, it relied on Siemens to prove that the integration could be done — and done with no pain to Sara Lee.

Indeed, these days, it is up to the MES vendors to step up their integration efforts. ERP software vendors, such as SAP, Oracle Corp., and even Microsoft Corp., are already entrenched in user companies. These ERP companies have spent the past few years rebuilding technologies around Web services and composite applications that are flexible. So ERP is in a leading role and doesn't have to prove much to its manufacturing audience. Rather, it's time for the MES vendors to step into the corporate spotlight. The question is, can MES deliver a great performance?

It was only a few years ago that industry observers and plant managers, alike, described MES as "a mess" — the result of an unruly evolution that led to a complex, monolithic footprint requiring mass-customization. In fact, many companies, Sara Lee included, didn't even use commercial MES applications, but rather pieced together their own homegrown solutions.

Understanding the need to make MES a strategic part of the manufacturing enterprise, many MES vendors are gravitating toward a new manufacturing enterprise model that is based on industry standards and maps out in very specific terms how to connect production operations with business operations in order to meet corporate initiatives. In devising the model, MESA International, an industry organization, broke up the monolithic MES monster into value-added pieces that have a direct impact on whatever key business processes are important to the end user.

The hope is that MES will take on new meaning. " 'MES' is still a term that people recognize and can hang their hat on, but when you get down to specifics, it means different things to different people," says Matt Bauer, director of information software marketing at Rockwell Automation and chairman of MESA International.