Some thoughts on legacy modernization with business rules

I saw this white paper by IBM on Legacy Modernization with business rules and thought I should quickly re-summarize my point of view on this and link to my various posts on the topic. The white paper does a nice, if IBM-centric, job of outlining the key issues:

You don’t need to modernize the whole application
Decision making components are often the highest change, most difficult to maintain pieces of mainframe systems
Externalizing these components using a business rules management system dramatically reduces the maintenance costs of a legacy application while both improving its agility and positioning you for replatforming later.

The basic steps:

Analyze the code to find the decisions
Rework the code to isolate these decisions in their own component
Work out the rules for these decisions and document them in a business rules management system
You can analyze the code to find rules but starting with the original policies/regulations is often much more effective as code analysis gives you VERY technical rules
Use the BRMS to redeploy the rules as a decision service that the legacy application can access
Retire the replaced code

READ

Leveraging Existing Data To Penetrate Saturated Markets

Read the white paper, even if you are not an IBM customer, as it is a nice summary. For those of you who want my opinion, check out these posts:

You can find these posts and more using the Legacy Modernization tag