Post By Charlie Heywood on October 28, 2019

Approaches to legacy system modernisation


The legacy of growth

The question of how best to modernise legacy technology systems is one of the most common, complex and impactful challenges faced by business owners today. Whether an organisation has grown slowly and steadily or experienced a phase of rapid extension; whether its development has been entirely organic or has involved mergers and acquisitions, and whatever the ultimate scope and sector of the organisation in question, the chances are that its enterprise technology, both hardware and software, includes some legacy elements. Sometimes lots of legacy elements.

It is easy to imagine that ‘legacy systems’ is a term that refers only to the very oldest and creakiest elements of an organisation’s IT infrastructure, but this kind of thinking is restrictive and even risky. Legacy systems can include the old and out-of-date, certainly – but they can also include elements which are simply no longer able to support all of the functionality required of the organisation today – or its goals for tomorrow.

Perhaps the organisation is wasting time and resource on manual tasks which could be accomplished digitally if two systems were able to speak to each other. Perhaps it wishes to expand and increase its total number of users, which will make the license for a particular application cost-prohibitive. Perhaps it wants to develop a new service, but current technology is unable to support this.

Whatever the drivers for legacy system modernisation, business leaders tasked with it have a hefty project and a lot of choices on their hands.

A juggling act for business

The fundamental challenge of any legacy system modernisation project is that it involves a huge number of moving parts – and these parts need to be juggled whilst the enterprise IT carries on serving the regular needs of the organisation. Considerations include:

  • Organisational strategy. Enterprise technology should always, always be chosen for its ability to support business strategy. The technology is there to enable the business, not the other way around. As such, goals, objectives, hopes and ambitions for the organisation should be the core drivers for modernising legacy technology, and should inform all of the choices around what is deployed.
  • Financials. Like any other enterprise technology project, costs need to be kept under tight control. Modernisation does not necessarily mean deploying a raft of new hardware and software – it might mean integrating existing applications. Businesses need to consider both capital and ongoing costs – which might include user licenses or cloud fees, depending on the technology chosen.
  • Integrations and compatibility. A common driver for system modernisation is enabling disparate systems to share information with each other, therefore reducing siloed information, cumbersome manual tasks and incidences of error. This can have a dramatic impact on efficiency but requires a careful approach to integration and converting data into forms that can be used across different systems.
  • Vendor management. Most enterprise technology infrastructures include multiple vendors and suppliers of hardware and software. Embark on a modernisation project, and the relationships with those partners are likely to change. IT needs to manage those relationships through periods of dynamic transition, ensuring that contracts are cost-effective, service level agreements are optimised and performance is top-quality.
  • Day-to-day operations. Throughout the change and (potential) disruption introduced by a major technology project like legacy modernisation, business leaders have ultimate responsibility for ensuring that the organisation can continue day-to-day operations as normal. Even a small outage or system failure as a result of the project could have a dramatic effect on the business bottom line, and if information is lost or corrupted as part of the project, then the impact could be devastating.
  • Security and compliance. Legacy modernisation typically involves moving data from one place to another, changing data from one format to another, and consolidating different forms of data. All this information needs to be protected from malicious intervention, and in line with whichever regulatory and legal frameworks the organisation is subject to. A legacy modernisation project can mean starting from scratch in terms of compliance audits.

Key steps to your modernisation strategy

So, with those considerations in mind, what stages should a business leader go through when planning and undertaking their modernisation project?

Define your drivers. Typically, these will involve an aspect of your existing technology infrastructure underperforming or being no longer fit for purpose. However, in line with the consideration of organisational objectives, you should also think longer term. What is your organisation likely to need from its technology in the future? What kind of user numbers and growth plans do you expect (or hope) to be dealing with? What applications or services might you be planning to deploy next year, and the year after?

  1. Don’t focus on saving your current system at all costs. It can be temping, particularly when the cost and complexity involved in the deployment of an existing system is still fresh in the memory. And as we will see, sometimes a refresh or reworking can drastically extend the life of a system you thought was hopeless. However, tying yourself to the existing system can result in a blinkered view as to what functionality you actually need, and can incur unnecessary cost and complexity.

  2. Standardise and simplify current applications and data before you begin. Essentially, the more simplification and rationalisation you can do before the project, the simpler the project itself will be. You don’t want to undertake a massive data migration only to then clean that data and find that half of it was never needed in the first place.

  3. Select the most appropriate technical choice based on the options we explore below. Don’t restrict yourself to thinking modernisation means brand-new procurement, or even working with the latest shiny vendor in your sector. Sometimes the most impactful modernisation projects simply involve breaking down siloes between two key applications, or moving data from a manual spreadsheet into a purpose-built platform.

  4. Plan, plan and plan again. Bearing in mind that normal operations must be maintained throughout your modernisation project, you need to have a clear awareness of how normal access to key applications and data will be maintained throughout.

  5. Deploy and test. As with any other enterprise technology project, you need to have a clear approach for testing the outcomes of your project, and measuring its efficacy and success.

Choosing a technical approach

There is no one-size-fits-all approach to legacy system modernisation. Tempting as it might be to assume that modernisation means rip and replace, or a blanket upgrade of the old, this is not the case.

There are, in fact, myriad technical options available, and it is possible to mix and match more than one in a single modernisation project. Here are some major strategies to consider.


In some ways the simplest, yet in others the most complex, this is a clean and drastic way of achieving modernisation. You decommission your legacy hardware or software and replace it with something entirely new – either a more advanced version of what you already had, or something else altogether.

Rationalisation and rebuild

Lots of different approaches may fall under this strategy. A full rebuild involves recreating your applications from scratch, perhaps preserving their original scope and specifications, perhaps reimagining, amending or extending them. A rearchitect process involves focusing on application code and reworking it so that the application can be shifted to a new platform with more potential. Breaking down applications into their individual working parts can enable the building of new virtualised, software-defined architecture, with greater potential for innovation and flexibility. At the simpler end of the scale, rationalisation and rebuild may simply involve migrating a dataset from a manual spreadsheet or siloed database into a more multi-functional application such as a CRM platform.

Outsourced hosting

Redeploying existing application components or workloads to virtual or cloud infrastructures can be a powerful way of generating more flexibility, scalability and agility. Doing so does not need to involve any recoding or deploying new applications, but it can still be transformative in terms of business processes.

API encapsulation

Encompassing multiple application features – or even multiple applications – behind a single application programming interface (API) can streamline and consolidate multiple functions, and create a more user-friendly experience for staff, partners and customers alike, depending on the context.

An open mind

Legacy system modernisation can feel like an overwhelming proposition – and certainly some such projects are dramatic in scale. However, very often in this area small undertakings can have a major impact. Simply rationalising and cleaning up your existing data, breaking down the silos between different sets or replacing a manual spreadsheet with an integrated digital database can massively speed up your operations, reduce errors and free up human resource to focus on strategic work.

In other words, legacy system modernisation – on a small as well as a grander scale – can unlock genuine digital transformation for your organisation.

Contact APH today to find out how we can help you achieve just that.


  • This field is for validation purposes and should be left unchanged.