While downsizing/rewriting legacy systems to open/newest system don’t follow legacy system design.

Actually there are two aspects that we tend to follow when downsizing legacy system. The first aspect is business logic and the second is system design.

Business logic: here I use to hear “It works perfect for the user so we duplicate it to our new system.” Although these argue sound reasonable I prefer to check up against the system bugs and requirements and to find out if maybe it’s the time to take advantage of system conversion and change system logic.

Design: As with business logic, many people tend to adopt the legacy system design and just find the right way to implement their legacy design using new development tool. I just argue that using this working paradigm is completely wrong. It’s completely wrong to use PL1 / natural design while developing .Net application and the same works for VB 6 application that convert to .NET. Usually design issues and other programming task are improved or even adopt by newest development environment thus leaving old problems already solved. Don’t get me wrong. I don’t argue that every legacy system design is wrong for new systems. I just say that you better redesign and check whether legacy design feet your needs. The old design can be achieved in much simple way or even cause defects to the newest system.