(this may sound like me bashing SAP. it's not. read on)
The benefits of Enterprise Resource Planning software do not come from the software itself, but from the changes you need to make to use the software.
If you've ever been involved in a SAP R/3 roll-out, you know it's not an easy process. Ditto for PeopleSoft, Oracle and Siebel. Most organizations use ERP software because they've grown large enough that home-grown solutions like emailing spreadsheets and keeping your HR docs in a SharePoint instance just don't work any more.
By the time your organization begins a SAP (or Oracle, or Xero, or ...) roll-out, you've lost customers or large piles of money (or both) because of miscommunication or business process inefficiency. The problem has made it's way to C-level guys, if not the board. By the time the corporation decides to spend the money and disrupt the business' status quo, the need is often dire.
At this point you call in the SAP Post-Sales support staff who start asking you a lot of questions about your business & your internal processes. They need to know the answers to these questions in order to configure various R/3 applications. But if you're like a typical SAP customer, your answer to a lot of these questions is... "Hunh. I don't know how we do that."
And then management finds out you're off-track with the R/3 roll-out and they either yell (bad managers) or start asking what they can do to fix it (good managers.) Eventually a business process consultant is hired and they start asking questions, looking for answers like "Yeah. We don't know why we do it that way. Bob set it up that way a couple years ago before he retired."
And there are ALWAYS a lot of answers like this.
After six months, just about everyone has talked to the business process consultant and he's built a reasonable model of your company. He gives your COO a thick binder filled with findings and recommendations. Over the next three months, they're phased in, R/3 apps are re-configured and your company goes live.
The following quarter everyone begins to realize how smoothly routine tasks are running. Sure, there are corner-cases that require people running around and some creative data entry, but those are the exceptions. Much less time and money is spent on routine business tasks (filling orders, tracking manufacturing, HR processes, expense reporting/reimbursement, budget forcasting, etc.)
And then everyone talks about how GREAT the R/3 suite is.
And it is pretty decent software. But here's the thing; about 80% of the benefits you received didn't come from the software itself, but from being open to the idea of modeling your business processes so they could be automated.
And that's why I say "using SAP R/3 does not make your enterprise better." After you modeled your business, you could just as easily continued to use emailed spread-sheets and half-broken wikis and you would still be a MUCH better business. That being said, you would probably quickly discover sharing data via spread-sheet is pretty sub-optimal and would move to something like R/3 or Oracle Financals/Fusion/Whatever.
And I like to remind CEOs & COOs that ERP software is not a magic bullet. Everyone has to dig into their daily tasks, figure out what their business processes are and how they inter-relate. And THAT is where the real benefits come from.