Buy 10 more years for your legacy applications

Without 'active' management, the application stack becomes a heavier anchor on an organization's ability to be agile and flexible. Thus, how an IT or application organization seeks to balance project and application portfolios has a strong bearing on the organization's future.Jim Duggan, Research VP, Gartner

In addition to this wisdom, Gartner also invented an excellent high-level tool for assessing applications based on their business value, cost, risk, technical efficiency. The model is called Tolerate – Innovate – Migrate - Eliminate or T-I-M-E. This model teaches how to reduce applications with little business value and low technical efficiency or excessive cost, to tolerate applications with low value but low cost and high efficiency, modernize those with high business value with low efficiency and excessive cost - and ultimately to invest on applications that already have high business value and high technical efficiency. If it is hard to follow the rules, Gartner has an illustration, which is much faster to absorb:

FRENDS integration platform as a tool for modernization

FRENDS integration platform has two main abilities that have an impact on modernization of the legacy systems:

• Host and engine for services (e.g. SOA, microservices)
• Host and engine for processes (e.g. BPMN processes and rules)

Services are built on top of existing enterprise applications utilizing their interfaces. Quite often services act like facades for legacy systems – thus bringing them from Modernize / Migrate slot towards Tolerate or Maintain slot. Another capability of FRENDS platform is Process Integration (BPM) that runs on top of the service layer of a company and its business partners. As a pervasive platform - FRENDS includes ESB, API management, managed file transfers, etc. but specifially "Services as facades" and Business Process Management are tools and practises that have immense value in the modernization of legacy systems. Using BPM as a process controller, it is possible to create rules and process flows that the old legacy application didn’t have built in – thus again push it upwards in quadrant towards Tolerance and Maintenance.

Services as Facades

The illustration below is a sample of process that runs on top of a service layer. Pervasive integration platform such as FRENDS can execute the process containing the logic and host the services as well.

It reminds me of a good old SOA, BPM approach, right? The pitfalls in this model are that services are tightly coupled with the underlying monolith legacy layer. The illustrations also assume that those monoliths have APIs as well. If we go and look the old legacy – so old it should be called vintage – there will be probably file interfaces or some ancient database system that can be accessed by FRENDS, but not in the pace and quantum of the queries that current business services need. The solution for this is quite simple – let’s pump the data to an intermediate database that can handle the load from services. The solution is simple, but consequences might not be that simple. For example, if the data is updated from the legacy system and simultaneously from the service layer we’ll need additional logic for decisions which update is the meaningful, compensating actions and so on. Nothing that smart design couldn’t handle, yet we’ll have to accept the added complexity as the probable price for the modernization. Following illustrations depicts this kind of sample architecture.

Another added value in this pattern is that it decouples that operative data from the underlying legacy system and open a magic gate to the land of independent and fully decoupled business services which could be – in time – considered quite like microservices. Or those functionalities can be migrated to some other new system. Nevertheless, this approach buys years of time for the old legacy to be renewed whatever the architectural approach in the future will be.

Want to know more? Contact Antti Toivanen.