Re: Thanks
The process of generating an MES or upgrade order was one interesting part of one of the jobs I had during my 20 years.
The starting point was a representation of the current system, in some kind of electronic form. If I had myself configured and ordered the original system, I probably had this information. Otherwise it required an attempt to reverse-engineer this, and there were pitfalls for the unwary. How many power supply units does the system have? How many memory modules and of what type? And so on.
Then I used a "configurator", initially on HONE (mainframe system running VM) and later on a PC. This was something created by the real product specialists describing all the possible features and the restrictions or co-requirements for them. In the configurator I specified the desired final system, eg one with more memory or whatever.
Then the configurator was set to work and it spat out a list of things required to upgrade the system - the MES if you will. This could include additional power supplies to support the additional components, for example. WIth all my specialist knowledge, this was too detailed to remember, so having the configurator work out the rules and generate the list of required upgrades was pretty vital. It would also list any components to be removed.
Then I'd pass this to a sales person, who would do something with the pricing to ensure that it was appropriate, and feed it into the order processing systems.
The configurator didn't stop all mistakes, but prevented a lot of them. The main problem was that it wouldn't let you order what you thought you wanted, until you worked out why, and it was normally my misunderstanding which was at fault.
Presumably something similar still exists today, but I left IBM in 2008.