Provisioning z/OS

This week I entertained a little talk about provisioning automation for z/OS. IBM has created a provisioning tool for z/OS that is part of the z/OS base. I talked about our experiences with the tool. It is changing to Ansible technology now. Next technology hop. Let’s talk tech again to refrain from doing things.

Later that same day I started a course called Google Cloud Platform Essentials.


We are somewhat behind on z/OS. That is a major understatement.

We done do tapes anymore, and MVSGENs, but it still feels like an upgrade from a horse to a steam engine.

Yet, I believe if done well the z/OS tools available today should allow us to catch up quickly.

There’s no technical obstacle. It’s only mindset.

Technical debt

  • Post category:Modernization
  • Reading time:2 mins read

Technical debt is a well-understood and well-ignored reality.

We love to build new stuff, with new technologies. Which we are sure will soon replace the old stuff.

We borrow time by writing quick (and dirty) code, building up debt.

Eventually we have to pay back — with interest. There’s a high interest on quick and dirty code.

Making changes to the code becomes more and more cumbersome. Then business change becomes more painstakingly hard.

That is why continuous renovation is a business concern.

Organisations run into trouble when they continue ignoring technical debt, and keep building new stuff while neglecting the old stuff.

Techies like new stuff, but if they are professional they also warn you for the old stuff still out there. You see them often getting frustrated with overly pragmatic business or project management, pushing away the renovation needs.

Continuous renovation must be part of an IT organisation’s Continous Delivery and application lifecycle management practice.

Making renovation a priority requires courage. Renovation is unsexy. It requires a perspective that extends the short-term horizon.

But the alternative is a monstruous project every so many years to free an organisation from the concrete shoes of unmaintainable applications. At best. If you can afford such a project. Many organization do not survive the neglect of technical debt.

The 80/20 principle

  • Post category:Principles
  • Reading time:3 mins read

The 80/20 principle also known as the Pareto principle applies to many areas.

The most common application of the principle is in the assessment of a project effort: 20% of the effort produces 80% of the job to be do done. Or the other way around, the last 20% of the work to be done will take 80% of the effort.

In IT, the principle applies also similarly to requirements versus functionality: 20% of the requirements determine 80 procent of the architecture. 20% of the requirements are the important ones for the core construction of a solution.

The principe thus tells you to focus on the 20% important requirements that determine the architecture. It helps you shrink the options you need to consider and prioritize and focus on the important parts of the solution.

The question is of course: which of the requirements are the important ones. The experience of the architect helps here. But in general you will realize while analysing requirements, if a requirement will need a significant change or addition to the solution.

A good book about the 80/20 principle is the book with the same name: The 80/20 Principle, by Richard Koch.

An example from an practitioner architecting an airline reservation system.

“The first time I (unconsciously) applied the 80/20 rule was in my early days as an architect. I was working with a team of architects on application infrastructure for completely new web applications. A wide variety of applications were planned to run on this infrastructure. However, it was not clear yet what the characteristics, the volumes, response time needs, concurrent users et cetera were for these applications, and that made it uncertain what we needed to cater for in this generic hosting solution.

So we decided to walk through the known use cases for the different applications.

We worked our way through four of the tens of applications. During the fourth we somehow could not come up with additional requirements for the application infrastructure. We realized that the rest of the set of applications would ‘only’ be a variety of one of the apps wealready looked at. So we had our 80% from looking at just 20%.”

Transition to obverse

  • Post category:General
  • Reading time:1 mins read

This blog is now transitioning. When I started the blog I wanted to write about IBM mainframe technology, giving space to other readers, presenting a fresh view.

My intentions have changed, challenges have changed, and readers have changed.

After some posts expressing somewhat obverse standpoints of mine, readers reacted they wanted more of that. Also, in an earlier blog I shared snippets called ‘Principles of doing IT’, which got positive feedback. In this blog I will now bring these together. I will categorize my posts so the reader can easily filter what he wants so see. Yet, I give myself the freedom to keep posting in the order I like, and on the topic that I feel most urgently needs an obverse view.

I hope you enjoy. Please let me know what you think.