Making software safer

Computer-based control systems represent both a major advance and a potential threat. The great advantage of the computer lies in its inherent speed, making possible the management of systems with a level of complexity far exceeding the capabilities of the human operator. The threat lies in the behaviour of the system in the event of a malfunction. Under these circumstances control will be lost; the outcome is at best unpredictable, and at worst catastrophic, since guided missiles, nuclear power stations, railway signalling, and military and civil aircraft are all dependent on software for their safe operation. The author shows how advances in fault detection in software offers the promise of better programs and a safer world