More and more MES vendors are positioning their products under the object-oriented rubric. This definition includes a host of capabilities: distributed systems, standardized applications tools for user interfaces and database connections, C++ objects that are transportable across architectures, and the use of third-party development tools that are easily extensible rather than proprietary user interfaces.
Take Texas Instruments, for instance. As part of a federally funded research program, the company experimented with object-oriented manufacturing applications. It was so encouraged by the results of the experiments that it applied the ideas to its larger semiconductor facilities in Dallas, Sh
erman, North Texas, Houston, and Lubbock. The result: an in-house MES called Works MES, comprising seven distinct systems that manage process, planning, scheduling, specifications, materials, equipment, and tracking.
According to Jack Mahaffey, Works product development manager at TI in Plano, Texas, it comes down to one issue: If you're really committed to using the object paradigm to the greatest extent, then "you don't want to distort the designs by forcing a separation of data and methods on your objects," he explains.
Staying true to form, TI selected the GemStone applications server from GemStone Systems to handle the object base. GemStone transparently stores complete Smalltalk objects in the database. "Most of the other object-oriented databases offer some level, some variant to that approach, but none of them is as pure as GemStone," explains Mahaffey. One way to look at it is obvious: In a manufacturing environment, where you're moving products through the factory, the products themsel
ves are the objects.
In a semiconductor-fabrication facility, for instance, the wafer objects, lot objects, and carrier objects contain the complete history of the processing that occurred on each wafer from every manufacturing step. To build a semiconductor device, a wafer will travel through 250 to 400 individual operations or steps where something on that wafer is transformed. "That gives you 400 opportunities to scrap the wafer," says Mahaffey. "It's worth it to maintain a very accurate history of what happened during the manufacturing process."
As the actual wafers move through production, there's a virtual wafer moving through the MES. So, there's a one-to-one mapping between objects in the real world and the objects that your system comprehends.
The Case for Object Orientation: TI+OO=MES
