(Via Cworld) In business, we find that like it or not, old code is still around, and it needs special care.
Legacy Software can be characterized as Cobol/mainframe code, code written fifteen years back, poorly documented systems that looks difficult to maintain, secure, reliable and effective stuff that just keeps running, year after year
The commonly held view about Legacy is that it was written by smart people a long time ago and it really works, instead of being the latest bug-ridden, bloated piece of garbage from some company that has only teenagers working for it. However you define legacy software, IT people say they know it when they see it, and they know it didn't all go away during Y2k remediation. It's the stuff with poor documentation, spaghetti code stirred by too many cooks, and processing cycles more appropriate for 1970s ways of doing business. And it's definitely not the stuff you tell college recruits about when they come looking for Java, Web services and grid computing. Yet a number of IT folks swear by it, not at it, saying they wouldn't dream of switching that trusty old accounting system they custom-coded in the 1980s for some newfangled commercial package with a seven- or eight-figure price tag.
But even the most enthusiastic of the legacy loyalists acknowledge that old software often presents special challenges. Although Tower is modernizing it in various ways - by adding Web services interfaces to other systems, for example - the underlying Cobol application is likely to serve the company for years to come, Grant says. "A lot of people get caught up in the wow and sexy stuff, but I've been a proponent of keeping what we have rather than starting all over, because I don't see the benefit," he says. Tower Records got its million lines of Cobol to its current useful and reliable state without a great deal of effort. Tower bought the software in the early 1990s from a small vendor that supplied point-of-sale systems to mom-and-pop video-rental stores. "The source code was terrible," Grant recalls, "and we had no documentation." Mainframe Cobol systems provide a model for modern distributed systems when it comes to security, maintainability and change management- it is like reinventing the wheel in the client/server world in terms of putting the disciplines in place that we already know how to do on the mainframe, say the mainframe afficianados.
Category :Legacy Systema