IT Management

Guy Harrison, senior vice president and principal architect at Computer Associates (CA), is an authority on mainframe computing. Before joining CA last year, he spent 29 years at IBM, where he was involved in the ongoing development of MVS and oversaw the transition to CMOS  technology. He ran the MVS program for much of his tenure at IBM. Harrison is an outspoken advocate of mainframe computing. As principal architect at CA, he’s working on software tools to simplify the management and operation of mainframe computers. Early this year, z/Journal interviewed Mr. Harrison.   

z/Journal: The experts regularly declare the mainframe is dead. Why doesn’t the mainframe die?

Guy Harrison: Frankly, sometimes we’re way too quick to throw the term “expert” around. When I ran MVS for IBM in the late ’80s and early ’90s, all the experts declared the mainframe a dinosaur headed for extinction. I said it was incorrect at that time and it’s still incorrect.  

The reason the mainframe doesn’t die is Reliability, Availability, and Serviceability (RAS). In the ’80s, cost was a fair concern, but since the mainframe moved to CMOS technology, the mainframe has been able to chase technology price/performance gains just like other systems. This made a substantial difference in the cost equation on the hardware side.  

Today, the mainframe is positioned to take advantage of technology gains in storage, memory, and CPU. Costs are dropping and continue to do so. Plus, you can run a mainframe at 90 percent CPU utilization. Try that with other systems and you would have a disaster pending.

Finally, all major applications today run on all platforms. You can pick the application you want and almost always find it for the mainframe.

So, what are the reasons people choose a platform: cost of hardware, applications, and cost of the people. If you look at the characteristics of the different platforms and consider cost and capabilities, the mainframe has become more cost-effective and has the application capabilities and operational characteristics that companies still want. That’s why the mainframe isn’t dead and has a bright future.  

z/J: Are new customers coming to the mainframe?

GH: Yes. New customers come to the mainframe for the reasons I mentioned previously: competitive cost, RAS, high CPU utilization, etc. But at the heart of the mainframe business remains the same customers, or at least the same kinds of customers, such as financial services firms, although the names of the customers may have changed due to acquisitions, mergers, and such.

A better way to look at this question is to ask where the new application workloads are going and whether the mainframe is getting its share. The answer is yes; the mainframe is getting its share and more. This is because applications are being written to run on a variety of platforms. Once written, you can run the applications where you get the RAS and utilization characteristics you want. For any decent size company, the mainframe will be the best place to run these new workloads based on its operational characteristics. However, this may not be the case for smaller companies due to the mainframe’s complexity.

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