Traps to avoid - having a moving target

If you want a new bathroom, you draw up a detailed plan, choose your tiles, choose your suite, and then commission someone to install it. What you do not do is create a vague idea of what you want, then change the layout when half of the bathroom has been installed.

Software development should be no different - no company can work effectively when you keep changing your mind. The best companies will insist on producing a fixed, signed-off specification before they begin building a system. The worst companies will bend over backwards to accommodate your every whim - and fail ever to produce a workable system.

One useful idea is to commission one company to draw up a specification for your system, and then submit this as your invitation to tender to other software companies. As a software supplier, it is very hard to estimate a price when you don't know what any possible final system is meant to achieve!