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Die-hard mainframe rationalization

Kevin Wornham
November 10, 2020

Oscar Wilde famously once said “reports of my death have been greatly exaggerated.” This quote could certainly be applied to mainframe technology, whose imminent disappearance has been predicted for many years. While the number of customers has decreased, its usage has continued – particularly within some of the largest companies – and remains especially strong in banking and retail.

However, as cloud continues to drive down IT costs and new cloud technologies narrow mainframe’s perceived advantages of reliability, availability, and security, it is seen more and more as just an expensive platform. Staffing challenges are also rising, as mainframe-experienced workers (who tend to be older) retire and exit the workforce.

The mainframe vendors argue that when you factor in total costs of running the workload, mainframe remains competitive. They have also been implementing new features in response to customer concerns to help reduce costs, improve integration with non-mainframe systems, run open-system software, and utilize Agile techniques and tools. Additionally, cloud-hosted Mainframe-as-a-Service provides customers flexibility and addresses system support skill shortages.

All these details need to be factored in as you plan your future mainframe strategy. Do you continue with your mainframe? If yes, should you increase or decrease its usage? If you’re looking to eliminate or reduce its usage, how quickly do you do this – and how/where/what do you replace it with?

The answer to these questions lies in analyzing the following five main approaches.

Mainframing the status quo

This means continuing with your current mainframe strategy and maintaining present applications – but not removing or adding to them. There may still be additional opportunities to reduce costs. Key areas include assessing the workload to look at:

  • Fully utilizing zSeries cost saving features such as zIIP, zAAP, IFLs, etc.
  • Obsolete jobs and processes still being executed
  • Performance-tuning opportunities
  • Reducing license and tool costs by eliminating or moving to cheaper alternatives.

Continue as a strategic platform

If your mainframe continues as a strategic platform, newer features will be adopted with the aim of integrating the mainframe into the larger landscape and reaping benefits from new techniques and design patterns. These include:

  • Implementing Agile & DevOps
  • Exposing data and workload via APIs and open standards to improve interoperability
  • Rearchitecting/Refactoring code and databases to create microservices.

Move horizontal workload

A move of horizontal workload generally retains the backend processing, database, and some or all of the business logic on the mainframe and moves/replaces the front-end and some business logic. This is done with the goal of retaining the workload that requires the mainframe’s strengths (i.e., reliability, security etc.), while moving the other workload to a less expensive platform or replacing it with components that have enhanced capabilities. The retained workload will leverage the newer technologies described above to enable easy interoperability with the new/replaced front-end.

Move vertical workload

A move of vertical workload shifts all layers for a workload from front-end interactions all the way through to back-end files and databases (i.e., moving the whole application). If the workload is – or could follow – an industry standard process, then the replacement could be an as-a-service or package solution. Moving the workload in this case may be as simple as remapping and shifting the data to the target.

However, if the workload has company-unique functionality that needs to be retained, it is likely that it will require a rewrite. Rather than start from scratch, business rules can be extracted from the existing system to speed up development and ensure matching functionality. Careful analysis is needed to identify obsolete and unused code to prevent propagating it into the replacement system.

Rehost workload

This entails moving workload from the mainframe to an emulated environment such as Microfocus Enterprise or OpenFrame that is hosted on cheaper hardware. These new platforms emulate many features of the mainframe, such as CICS and JES, which enable programs to be moved by recompiling with few or no changes at all. The workload is then able to be quickly moved and continues to be maintained by existing staff.

However, while these environments emulate a lot of common components and can support or transpile some programming languages, it does not support them all. Therefore, alternatives to some components will be needed and some languages and databases must be converted. A company may use more than one of these approaches in drawing up an effective mainframe strategy. For example, it may rehost the workload to obtain some quick savings while they work on replacing it with new applications or designate the mainframe as strategic. Although, this is only for some of the workload, so undertaking a modernization and workload removal approach is recommended here.

Capgemini’s CAP360 suite includes all the tools you need to help your organization plan and execute your mainframe transformation. These include high-level analysis tools to help define your strategy and approaches, and deep technical and code-level parsing tools to identify interdependencies, redundant components, and optimizations, along with business-rule extraction and DevOps tools.

CAP360 is part of Capgemini’s ADMnext offering, which can drive your transformation as a stand-alone program or include it as part of a more comprehensive managed service agreement.

This blog is authored by Kevin Wornham. To learn more about what CAP360 and ADMnext can do for your mainframe rationalization strategy and business as a whole, contact Kevin here.