System requirements management

This paper considers the importance of managing requirements as one of the keys to ensuring successful systems development. Sources and types of requirements are discussed along with how they are expressed and their place in the system lifecycle. The use of tools to assist with requirements management is considered and some of the pitfalls to avoid are given. The purpose of the paper is to provide an introduction to the subject, with a particular bias towards railway signalling system requirements (although the principles hold good for any type of system).