ABSTRACT
Software lies at the heart of all information technology (IT) systems. Such a statement of the (apparently) obvious may seem superfluous in a book on IT systems validation, but the need to reemphasize it is pressing. Because of its complexity and the fact that its structure and detailed functioning are understood only by a small eclectic group of individuals, the importance of ensuring its validatability at the outset of an IT system validation project is frequently underestimated. Indeed, there have been many instances in the history of regulated industries when the issue has been ignored altogether.
