Rather than rewrite older business applications, consider using a method such as APIs, stored procedures, or UDFs to access legacy app functions
By Laura Ubelhor and Christian Hur
Making the decision to include Web applications as part of your business systems doesn’t mean you have to scrap the applications already in use. It might make sense to leave some of these applications as they are, and only deploy select applications on the Web. Many organizations already have applications in which they have invested considerable resources, time, and money. Many of these applications are stable and still well suited to the business requirements. There is no reason to rewrite all your applications unless a business need requires a change.