When we were surveying the market for enterprise software SAP was one of the systems we reviewed.
Several of our customers have implemented it, and it is a nightmare. Software is supposed to facilitate a company's operations - but with SAP (an apt acronym) it's the other way around. Our customers have adopted some really stupid business practices because of this ridiculous software.
A medium size SAP customer gave us a pitch about why it had been so good for him to go with SAP. Problem was, he'd spent nearly as much on consultants as we had for our whole system !
And we run rings around them for efficiency, ease of use, excellent reporting, excellent linkages - we love our system. We implemented over New Years 1999. Finished the year with one system and started with our new one, and haven't looked back. We had around 500 active work orders during the transition.
Want a good system ? Try Visual Manufacturing by Lilly.
Implementation of SAP is 5-7 times the cost of the software. In a Fortune 1000 size company, upwards of $100M to implement.