Legacy systems remain critical to many (most) organizations and so legacy modernization is still a hot topic (which is why we have a webinar on legacy modernization coming up with our partner TechBlue). With that in mind, as at is has been a while since I blogged on this topic, I thought I would share a few thoughts. First, this week, four key reminders when modernizing legacy applications:
- You don’t need to modernize the whole application
Often you can dramatically improve a legacy application by modernizing just part of it. Many pieces of legacy applications work just fine and have few, if any, change requests pending. Maintaining these pieces as legacy code is not expensive and replacing it all would be high risk so why not leave it alone while focusing on the pieces that don’t work well, especially the pieces that have high maintenance costs.
- Decision making components are often the most costly to maintain pieces of mainframe systems
Decision-making is often high change with new regulations, new policies, competitive response and evolving consumer/market conditions driving a need to make changes to these components. Often the part of a legacy application that causes most of the maintenance cost is a decision-making component – the way a fee is calculated, the way an application is validated, the way a claim is checked for eligibility must constantly be changed resulting in big legacy maintenance bills and long periods where the system works incorrectly or inconsistently with the business need.
- Externalizing these components using a Business Rules Management System (BRMS) dramatically reduces maintenance costs
If the high change, high cost components are externalized then you can improve the agility of your current legacy application. Externalizing this decision logic means it can be more readily changed reducing the time and cost to make needed changes. In addition decision-making logic is typically rich in business meaning and the use of a BRMS means that this logic can be exposed in a way that directly enables business owner participation in rule maintenance.
- It is often the decision-making in a legacy application that needs to be shared.
When organizations talk about needing to connect new web or mobile apps to existing mainframe applications what they often mean is that they need the decision-making from that mainframe application to be shared so that validation or eligibility is consistent. Externalizing decision-making means this decision logic can be available for new systems.
Next week I will describe the basic steps for getting from where you are to where you need to be. Meanwhile don’t forget to register for the webinar – Best Practices in Targeted Legacy Modernization in Government – on March 5.
Cross-posted from JTonEDM.