So how do you deal successfully deal with mergers and acquisitions? Given how crucial integrated systems are to a successful acquisition, it's a crime how infrequently and how late CIOs are brought into the deal-making process. Even so, there are ways, maintains Forrester Research analyst Alex Cullen in a new report, for CIOs to have a positive influence—and help ensure that M&A stands for more than misery and agony.

Q: I once talked to a CIO who knew that his CEO was going to grow the company by acquisition, but he knew he'd probably be the last one to know that something was being planned. He just went ahead and created a plan without knowing what the acquisition was.

A: That's exactly the right thing to do. That gave him time to think about his own capability to execute on the plan. He had time to determine where his department was weak in terms of integrating an acquired company and where it was strong and what he was going to need when he was surprised.

Q: The other interesting thing this CIO said was that because his company was in a vertical industry—in this case, aviation—he knew that there was a limited universe of industry-specific applications he'd have to think about integrating and he could be prepared for those in advance as well.

A: He did the right thing. He could figure out what questions he would ask. The other thing about knowing you're going to grow by acquisition is that with each subsequent acquisition, you get more knowledgeable and the CIO gets brought closer to the beginning of the due diligence process that goes on during every acquisition.

Q: What goes on during the due diligence process?

A: There are two phases: preoffer and postoffer. It's not common that CIOs are brought in for preoffer due diligence. If they are, it's to see if there are any show-stoppers or expense items that might come back and cost the acquirer more than it might expect. They should be brought in preoffer to get a sense of how easy or hard it's going to be to bring the firm into the fold, much like having compliance staff look at the acquired company's financial controls. You want to figure out if this firm going to be easy to fold in or not.

Q: How often have you seen a deal killed because of what the CIO offers in due diligence?

A: A deal may be killed, but it's because the CIO drives the nail into its heart. It's because of that in conjunction with other problems.

Q: So what happens postoffer?

A: You have to remember that in every deal, the CEO gets up and tells the stakeholders that within a certain period of time, the two companies are going to get synergy from the deal. On the day the deal's closed, the CEO is going to be impatient for all those synergies to get in place. So between the time the deal is announced and it's closed—usually three to nine months, depending on the size of the companies—the CIO has to make developing a plan the No. 1 priority, getting as much detail as possible regarding the other company's systems and yours.

Q: That sounds difficult.

A: It's true that there's a bit of an art there. CIOs just have to make sure they don't hang themselves by claiming something too aggressive. As I said, serial acquirers get better with experience and they get the CIO involved earlier. When that happens, the CIO has a better sense of the business intent of the merger and how that will affect IT. If the business intent of the deal doesn't require close integration—you're just buying up customers or employees—you can realize synergy quickly. If it's a true merging of two companies into one, with a shared distribution and business model, that takes longer. Is there a lot of like-to-like integration? Is the acquired company's data structured differently? That's where it might take a year or two before synergies appear.

Q: You mentioned that there were three phases to a merger.

A: Yes, first you connect the infrastructure, so there's a common network with common e-mail. In phase 2, you start doing basic business integration, bringing the applications together and shutting down the stuff you don't need. Phase 3 is that day of synergy the CEO spoke about, where the vision of how the merger transforms the business comes true. Knowing what that vision is will help you be smarter about how you integrate everything else.

Q: So it really comes down to IT alignment—the IT department's knowing the business' goals.

A: Yes, and reflecting back to the business what the business wants to achieve to make sure it understands clearly. That's the first conversation the CEO and the CIO should be having: What should the result look like when it's done?

Q: Is your advice different depending on whether the CIO is a target or an acquisitor?

A: Normally I focus on the acquisitor role. If you're the target, you have very little control. You're really only an advisor on what systems you've got, and frequently the acquiring company is not very good at listening to your advice. I did talk to a CIO who was first on the acquiring side and then on the acquired side, so he'd seen both angles. It was a good experience when he was acquiring, but when he was being acquired, he was shocked at how poor the due diligence was. That was two years ago; he's gone, but the acquiring company still hasn't figured out what it wants to do. It still has a proliferation of incompatible applications, and it hasn't been able to cut back staff. One piece of advice I didn't put in my report that I should have: Listen to the people you've acquired.

I do know of one other case where it was the acquired firm's CIO who was kept on, because management thought he was better than the CIO they had. That was a special case, in part because the acquiring firm had a lot of respect for the management of the acquired firm and made a deliberate decision to combine both staffs. That was truly an exception, but it shouldn't be dismissed. Think about how you might want to impress the people who are buying your company.

Feedback question: Tell us your best and worst experience during an acquisition.

Q&A conducted by contributing Web editor Howard Baldwin.