There are plenty of very useful tools in the market place covering requirements management, however, few, if any, of the current toolsets deployed or the processes followed address validating the requirements.

Requirements are the corner stone of a system and at no point during the V cycle are they validated.

Requirements are often still written in Word and Excel, which are products that have been co-opted to assist in natural language writing. Useful for syntax, but not for semantics or simulation.

Requirements Management and Requirements Traceabilty, with tools such as DOORS , aren't Requirements Engineering either, valuable though they may be. Even a set of formally proven requirements doesn't guarantee that the behaviour of the system is as expected. Modelled behaviour might respect some properties, but who checks that the property is the right one or that it reflects the intention of the designer.

It is therefore evident that current products and processes do not answer these fundamental questions:

Does my system, as I've described it, do what I mean it to do?

Have I written anything conflicting ?

Have I missed anything?

Is what I've written completely unambiguous?

If these questions can't be answered then specifications generated during the requirements phase are almost certainly flawed and nothing can be validated against them.

Engineering is a creative activity during which an engineer will imagine, then create a certain artefact and then, as an engineer, he will challenge himself as rigorously as possible, test his creation so as to validate it and make sure the quality level is sufficient, before handing over his results to the next player in the development process. It is time for Requirements and Systems Engineers to be given the proper tools to perform their jobs in the same way that system designers, coders and testers have.

Let me introduce you to STIMULUS , the world's first modelling and simulation tool enabling you to write, edit, debug and test functional, real-time systems requirements - including architecture and interface description, state-machines and use cases - in the same way a programmer would develop a piece of code.

STIMULUS : The Model-Based System Engineering tool with Requirements-In-the-Loop simulation.

For a demonstration, please contact me at ken.nathan@argosim.com or + 44 (0) 7584 994 997