Jeff Clarke has been driving some big changes at Computer Associates (CA) since the surprise departure of Sanjay Kumar.

After shooting through the ranks, first at Digital then Compaq and then HP, he was taken on by CA as chief financial officer less than three months ago.

He now also has the role of chief operating officer since former chief executive Kumar moved on. So with only an acting chief executive in Ken Cron, Clarke is effectively running the company.

Clarke left HP to join a company facing a US Securities and Exchange Commission (SEC) investigation over alleged accounting problems.

A financial officer by training, he has the legitimate track record in financial probity that will please analysts and the SEC. And as Compaq's lead man on the team responsible for the merger with HP, he has an eye for the 'big picture'.

So with the world at his feet at the newly-merged HP/Compaq, why give it up to join CA? Clarke explained that he considered a number of options. "Then I looked at CA. It was a company that had exactly the right products strategy," he said.

What about the problems at CA? For Clarke, they are mostly a thing of the past. "CA had made some of the difficult moves towards this new business model, towards conservative accounting, and I could see an opportunity where I could add value as a financial executive with a large operational bent," he explained.

"So I could help run the company but also put in some very, very strict and important changes around the link between operations and finance, and around conservative accounting, structural changes and so on."

And Clarke has no doubt about the competitive position of CA. "This is a company with one of the most exciting market positions in the industry," he said.

"As companies go to grid computing, the key underlying infrastructure is going to be the management infrastructure software. That's all about flexibility of computer resources, and that is what CA brings to the table. Couple that with security, storage and databases and you have some key components."

But can he cope with sorting out the financial problems (and calming the SEC and investors) while running a business the size of CA on a day-to-day basis as well?

"I have a broad set of experiences and I have managed large operations in large companies. It is a great chance for me to really dive in," he said.

And dive in he has, into what some would argue is the deepest of deep ends. The ongoing SEC investigation concerns the year 2000 and 2001 accounts, and claims that CA booked sales too early and put them in one quarter rather than the following quarter to help the company hit targets.

These sorts of accounting practices have dogged the software industry for years, but Clarke sees this as the perfect opportunity to deal with the issue once and for all.

But this is the chief financial officer's domain, and Clarke is chief operating officer as well. Isn't this blurring of roles how the trouble started in the first place?

"We would put a credible structure and checks and balances in place to ensure that never happens again," said Clarke.

"We will put in a new finance executive, a controller for the sales force, one for the direct sales force and one for the channel sales force. That person will certify the results of their operation and ensure that the accounts are appropriate."

Along with greater financial control, CA has been running a new accounting system for three years that takes the pressure off the company and the customers.

"The new business model is the most conservative possible for the software industry. We are one of the first companies to adopt this and it has a series of business and accounting benefits," explained Clarke.

"From the customer point of view it is more flexible in its terms and conditions, more flexible on payment terms - a series of things add flexibility.

"You can mix different products in and out and that is a very big advantage to customers. It makes it easier for our sales people, too.

"With the standard model, most companies are always trying to close the deal in the quarter so they can meet the quarter. Now, because of this variable recognition we can be more flexible because the timing does not matter that much."

Isn't this like the salesforce.com, pay-as-you-go model, which is ultimately flexible because the customer only pays for what is being used?

"Yes, and it plays perfectly to our strengths," claimed Clarke. "We can do monthly payments now. We can do whatever the customers wants. We don't have that constraint that other companies do, because we are two-and-a-half years into the transition away from having to hit that revenue in each quarter."

So what is next for the fast-moving Clarke? The vacant chief executive's position, perhaps?

"I'm very busy as the chief financial officer and chief operating officer, and the company is going to look outside for a chief executive. So I will be the chief operating officer on a 'go-for-it' basis," he said.