Many lines are built on the experience gained from having built previous lines, and incremental improvements creep in. In other cases, capital costs may discourage modifying one line to mimic another. Nor do the differences divide neatly along corporate lines. A steel company might operate two plants, one for making steel and one for stamping it into parts. The businesses are closely related, but their systems needs will differ because, among other things, the stamping plant might shut down every day, whereas the steel mill's furnaces don't.
Specializations can also exist by industry.
A gasoline refinery has a very different set of software needs from that of a cake-mix factory. The key, he adds, is to insist on standard interfaces but to give every manufacturing facility autonomy. In the end, you have to understand where it makes sense to try to compartmentalize systems so that you have natural break points, Swanton says. You've got to let each factory implement its own systems as long as it gets a common information structure and a common reporting mechanism to the enterprise as a whole. A generation of high-capacity, portable and removable storage drives is offering new opportunities for those who need to secure data or take it on the road.