Our objections to the mainframe are firmly rooted in what the platform was, not what it is. That does not necessarily make it the best platform for everyone’s needs, but it does alter the criteria by which it is accepted or rejected.

By “mainframe” in this context we mean the IBM System zEnterprise. Launched in July 2010, it is the culmination of an evolution over 30 years of mainframe technology which has succeeded in marrying the security, reliability, availability and scalability benefits of its forebears with the sort of versatility that client-server environments offer.

While the number of workloads handled by the mainframe, and specifically the IBM System z, continues to grow, it is still not considered as a realistic proposition by many potential users.

This paper examines their objections in detail, shows where they are justified, and demonstrates that, with objective cost/benefit and risk analysis, many IT departments would do well to reconsider the mainframe.