Making mainframe applications more agile, Gartner – Highlights

In a report giving advice to mainframe folks looking to be more Agile, Gartner’s Dale Vecchio and Bill Swanton give some pretty good advice for anyone looking to change how they do software.

Here’s some highlights from the report, entitled “Agile Development and Mainframe Legacy Systems – Something’s Got to Give”

Chunking up changes:

  1. Application changes must be smaller.
  2. Automation across the life cycle is critical to being successful.
  3. A regular and positive relationship must exist between the owner of the application and the developers of the changes.


This kind of effort may seem insurmountable for a large legacy portfolio. However, an organization doesn’t have to attack the entire portfolio. Determine where the primary value can be achieved and focus there. Which areas of the portfolio are most impacted by business requests? Target the areas with the most value.

An example of possible change:

About 10 years ago, a large European bank rebuilt its core banking system on the mainframe using COBOL. It now does agile development for both mainframe COBOL and “channel” Java layers of the system. The bank does not consider that it has achieved DevOps for the mainframe, as it is only able to maintain a cadence of monthly releases. Even that release rate required a signi cant investment in testing and other automation. Fortunately, most new work happens exclusively in the Java layers, without needing to make changes to the COBOL core system. Therefore, the bank maintains a faster cadence for most releases, and only major changes that require core updates need to fall in line with the slower monthly cadence for the mainframe. The key to making agile work for the mainframe at the bank is embracing the agile practices that have the greatest impact on effective delivery within the monthly cadence, including test-driven development and smaller modules with fewer dependencies.

It seems impossible, but you should try:

Improving the state of a decades-old system is often seen as a fool’s errand. It provides no real business value and introduces great risk. Many mainframe organizations Gartner speaks to are not comfortable doing this much invasive change and believing that it can ensure functional equivalence when complete! Restructuring the existing portfolio, eliminating dead code and consolidating redundant code are further incremental steps that can be done over time. Each application team needs to improve the portfolio that it is responsible for in order to ensure speed and success in the future. Moving to a services-based or API structure may also enable changes to be done effectively and quickly over time. Some level of investment to evolve the portfolio to a more streamlined structure will greatly increase the ability to make changes quickly and reliably. Trying to get faster with good quality on a monolithic hairball of an application is a recipe for failure. These changes can occur in an evolutionary way. This approach, referred to in the past as proactive maintenance, is a price that must be paid early to make life easier in the future.

You gotta have testing:

Test cases are necessary to support automation of this critical step. While the tooling is very different, and even the approaches may be unique to the mainframe architecture, they are an important component of speed and reliability. This can be a tremendous hurdle to overcome on the road to agile development on the mainframe. This level of commitment can become a real roadblock to success.

Another example of an organization gradually changing:

When a large European bank faced wholesale change mandated by loss of support for an old platform, it chose to rewrite its core system in mainframe COBOL (although today it would be more likely to acquire an off-the-shelf core banking system). The bank followed a component-based approach that helped position it for success with agile today by exposing its core capabilities as services via standard APIs. This architecture did not deliver the level of isolation the bank could achieve with microservices today, as it built the system with a shared DBMS back-end, as was common practice at the time. That coupling with the database and related data model dependencies is the main technical obstacle to moving to continuous delivery, although the IT operations group also presents cultural obstacles, as it is satis ed with the current model for managing change.

A reminder: all we want is a rapid feedback cycle:

The goal is to reduce the cycle time between an idea and usable software. In order to do so, the changes need to be smaller, the process needs to be automated, and the steps for deployment to production must be repeatable and reliable.

The ALM technology doesn’t support mainframes, and mainframe ALM stuff doesn’t support agile. A rare case where fixing the tech can likely fix the problem:

The dilemma mainframe organizations may face is that traditional mainframe application development life cycle tools were not designed for small, fast and automated deployment. Agile development tools that do support this approach aren’t designed to support the artifacts of mainframe applications. Modern tools for the building, deploying, testing and releasing of applications for the mainframe won’t often t. Existing mainframe software version control and conguration management tools for a new agile approach to development will take some effort — if they will work at all.

Use APIs to decouple the way, norms, and road-map of mainframes from the rest of your systems:

wrapping existing mainframe functions and exposing them as services does provide an intermediate step between agile on the mainframe and migration to environments where agile is more readily understood.

Contrary to what you might be thinking, the report doesn’t actually advocate moving off the mainframe willy-nilly. From my perspective, it’s just trying to suggest using better processes and, as needed, updating your ALM and release management tools.

Read the rest of the report over behind Gartner’s paywall.

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