After looking at the history of the mainframe, how you’re using it, why you might replace it and how to do so, we’re now asking – how do you bring it all together?
The mainframe is an important but complex tool in an organisation’s tech stack. This series has already examined the mainframe’s history and use today; the drivers for change that you might look at when considering a migration; and the next steps to take after you’ve evaluated your existing environment. But we haven’t seen how to bring it all together.
NWT is an independent consultancy specialising in mainframe migration. To do so, it uses the ‘4D Framework’, the stages of which are Discover, Develop, Decide, Deliver.
The foundation for a mainframe migration is the Migration Assessment, which covers the first three phases: Discover, Develop, Decide.
The purpose of the Discovery phase is to understand all aspects of the current mainframe services, covering the existing systems/applications and their characteristics, the underpinning infrastructure/middleware, and any critical inter-dependencies. Key deliverables from this phase include applications, hardware and communications inventories.
The Discovery phase also includes an analysis of what the migrated workload will look like, based on mapping the systems and applications onto the current business processes and services to demonstrate each application’s role in supporting the business. Placing the existing applications in their business context is essential to making informed decisions about the strategy to be pursued and migration priorities.
Discovery plays a critical role in understanding all the moving pieces of your IT environment, and has never been more relevant in a landscape that includes multiple vendors, splits in responsibility, accelerated innovation delivery and greater emphasis on automation. A well-executed Discovery phase will give you the information you need to fully understand the best options for your business and the process to be followed. It will enable you to ignore the myths about the usability or viability of the mainframe and ensure the cost, benefit and risk associated with switching technologies have been fully considered in arriving at an objective assessment of the best way forward for your business.
The output from the Discovery phase provides the insight and understanding for the Develop phase, and enables specialists to work with clients to develop the migration strategy. This strategy sets out the options relevant to each mainframe service under consideration – which should be migrated, modernised, retired, replaced or even maintained on the mainframe. The consultancy will also analyse the risks associated with the migration, return on investment and estimated costs. A plan for delivering the migration completes the Develop phase and covers prioritisation of activities based on business priorities, as well as identification of specific applications/services to be migrated as pilot projects.
Once the Develop phase is complete, the Decide phase will review the migration plan with key stakeholders and agree any adjustments to the plan in readiness for sign-off to proceed to the Deliver phase. This completes the Migration Assessment.
There are several approaches to help ensure a successful migration. NWT’s is based on the mantra of, “Think big, start small, scale rapidly, learn and adapt…”. What this means for mainframe migration is that the Discovery phase will consider the bigger picture in terms of the wider business context in which the mainframe services operate, but will break the migration down into smaller, manageable projects. Some of these projects will be identified as pilots, which will be used to prove the approach and the technology. The lessons learned from these pilots will enable the programme to scale rapidly and at low risk through the adoption of changes to reflect the experience of delivering the pilot projects.
A migration assessment is not a one-off activity, but an iterative one. It incorporates an adaptive feedback loop that helps ensure the success of the programme as whole by learning from the experience gained in the early parts and adapting the approach to subsequent parts.
Start a legacy migration assessment as part of your Discovery phase as soon as possible, and before the need to do something becomes urgent. This will give you the time to undertake a comprehensive Discovery, which will enable you to identify and fully evaluate all options and help ensure you choose the best way forward.
As a first step you will need to identify all the key stakeholders – those who have a vested interest in the existing legacy environment and operations, as well as the future operating model and IT environment. Alongside this you need to identify the experts in your organisation who really understand both the business (in terms of risks and processes) and IT environments and operations; they will be critical to establishing a full understanding of what’s there today and what ‘good’ looks like for the future. They must be freed up from their day-to-day responsibilities in order that they can devote sufficient time to effectively support the programme.
Key to ongoing success is the programme sponsor – someone drawn from the senior management team whose role is to ensure the programme gets the support and commitment it needs from the Board as well as all impacted areas of the business. And finally, whilst you are the experts in your business (no-one knows and understands it better), also recognise where you will benefit from engaging external help to provide expert guidance derived from real world experience of similar programmes. This is especially relevant to the programme/project management and technical solution architecture.