Our Tuning Letter subscribers have probably read our article on A Holistic Approach to Capacity Planning in our Tuning Letter 2015 No 4 (pages 55-75). Or you might have seen our SHARE presentations (one is The Cheryl & Frank zRoadshow, SHARE 2016 in San Antonio) where Frank discussed activating more CPs in order to reduce the CPC utilization, lower the RNI, and lower MLC costs. Todd Havekost from IntelliMagic also covers this in his conference presentations (see Achieving Significant Capacity Improvements on IBM z13: User Experience) – Todd worked in the company that our original article was based on (USAA). Some customers could benefit from this approach (as USAA did), but others might not – it is a classical mainframe ‘it depends’ type of situation. In the Tuning Letter article, Todd and Frank listed 14 suggestions of things to do before attempting this. In his presentation Frank had fewer (in the interest of time), but every time we talk about it, we stress that you need to look at ALL the costs of providing your z/OS service, not just MLC.
Unfortunately, not everyone is getting that word. We’re hearing about people who don’t consider their ISV software costs or even ALL of the IBM product costs (such as IPLA software and hardware maintenance) before activating or acquiring more CPs. If you don’t perform a thorough study of both the software and hardware costs beforehand, you could be rudely surprised. Look before you leap!