From BIT Chapter one: Data Processing and the IBM Mainframe

An introduction to chapter one of BIT - on the IBM mainframe culture, it's history, terminology, and operating beliefs.

From Chapter one: Data Processing and the IBM Mainframe

This is the 2nd excerpt from the second book in the Defen series: T Business Information Technology: Foundations, Infrastructure, and Culture


The IBM mainframe or data processing information systems architecture consists of:

  • IBM System 360 compatible and successor hardware;
  • JCL, DOS 360, IMS, CICS and successor software;
  • Data center management methods or processes; and,
  • A transactions oriented business or organizational context.

As of late 2007 there were about 18,000 mainframe data centers in operation worldwide. Some amount to billion dollar businesses but, on average, each spends an estimated 46 million (USD) per year; the vast majority of it on staff, desktop support, and facility services. Taken together these data centers cost their owners nearly eight hundred Billion dollars to operate.

Originally data processing centers focused on developing reports summarizing business data well after that data was generated by normal business processes. Although reductions in that time lag have allowed many data center operations to get closer and closer to real time business support, the general focus remains on a class of tasks that can fairly be described as automated clerking.

As part of that after-the-fact focus on clerical automation most data centers were initially created to reduce processing costs in Finance, and cost justified mainly on the basis of either displaced clerical wages or increased accuracy in clerical tasks. As a result the Information Systems Director has traditionally reported through the Finance department and focused on cost cutting.

Many companies now also have Chief Information Officers (CIOs) and Chief Technology Officers (CTOs) to, or through, whom the data center reports to a steering committee of some kind. In general, however, today's mainframe data centers remain separate from the rest of the of the business and are usually still put into the organizational context as a corporate resource budgeted as overhead - and whether that overhead burden is carried on a centralized or departmental basis doesn't usually affect operations.

Consider, for example, the distancing between data center operations and the rest of the business implicit in the following quotation from a November 2002 interview with John Hagell III, author of Out of the Box: Strategies for Achieving Profits Today and Growth Tomorrow Through Web Services (Harvard Business School Press, Oct. 2002):

Computerworld: "Who are the early adopters?" (of web technologies)

Hagell: I'm seeing two parallel paths. One is within the IT department where there are early adoption efforts to see how it works and how it can help integrate systems. The other is coming from the business side, where executives are faced with having to reduce capital budgets by 25% to 30% and they're looking at web services as one way of doing that. To date, there's been more focus by Business than by IT.

From an outside perspective the mainframe data center is Dilbert country. The prevailing ethic is management by documentation with emphasis on continuity of processing, continuity of methods, and continuity of roles. ---

Some notes:

  1. These excerpts don't include footnotes and most illustrations have been dropped as simply too hard to insert correctly. (The wordpress html "editor" as used here enables a limited html subset and is implemented to force frustrations like the CPM line delimiters from MS-DOS).

  2. The feedback I'm looking for is what you guys do best: call me on mistakes, add thoughts/corrections on stuff I've missed or gotten wrong, and generally help make the thing better.

    Notice that getting the facts right is particularly important for BIT - and that the length of the thing plus the complexity of the terminology and ideas introduced suggest that any explanatory anecdotes anyone may want to contribute could be valuable.

  3. When I make changes suggested in the comments, I make those changes only in the original, not in the excerpts reproduced here.