Shop Order Close

We're on version 4.0.5, and would sure appreciate some help with the shop
order close process.  We went up on BPCS in March '95, and were told at that
time by our consultants not to run Shop Order Close (CST900, as we have
costing installed), as we wouldn't be able to make adjustments to shop
orders.  Now, I'm sure they meant that to be a temporary thing, as we went
through the initial learning process, but 4 1/2 years later, we still
haven't done it!

The biggest reason we need to do it, we've discovered, is that we would like
to do some clean-up in our item master, but you can't inactivate an item
master that has a shop order.

I called the SSA help desk on this, and they warned me this may take in the
neighborhood of days (or weeks?!) to run the first time, as we have 220,000
records in the FSO file.  (He said most people run this process at least
weekly ... whoops!)

I've played around with this in a test envionment, and it's going to be a
real pain, I can tell.  We also have performance measurement installed
(although we've never used), which apparently means I have to close each
period for each facility individually before I can even do CST900.

Does anyone have an easy solution?  All I really care about is cleaning up
my FSO (and, I suppose, the FMA) so that I will be able to inactivate some
item numbers ... I don't care about performance measurement, the costing
stuff, etc.

Any suggestions would be welcome!