Strategies for managing requirements creep

One of the most chronic problems in software development is the fact that application requirements are almost never stable and fixed. Frequent changes in requirements are not always caused by capricious clients (although sometimes they are). The root cause of requirements volatility is that many applications are attempting to automate domains that are only partly understood. As software design and development proceeds, the process of automation begins to expose these ill-defined situations. Therefore, although creeping requirements are troublesome, they are often a technical necessity. Several threads of research and some emerging technologies are aimed at either clarifying requirements earlier in development or minimizing the disruptive effect of changing requirements later