60% of control system accidents `are waiting to happen`

The Health and Safety Executive has updated is guide to improving the safety of control systems in industry. The guide* analyses 34 incidents - 12 of them in detail - and shows how they could have been avoided.

About 60% of the control system failures in these incidents were waiting to happen before the system started to operate. Of the 34 incidents, 44% had inadequate specification as their primary cause, 20% resulted from changes after commissioning, 15% were attributed to design and implementation, a further 15% to operation and maintenance, and 6% to installation and commissioning problems.

"This guidance allows everyone involved in the development and use of control systems to learn from others and avoid repeating disastrous mistakes," says Paul Davies, HSE`s chief scientist. "It provides a good introduction to the issues to consider when building and relying on a control system for safety, and points to many sources of further information."

* Out of control: why control systems go wrong and how to prevent failure (2nd edition). Price £11.95 from HSE books. Details on +44 (0) 1787 881165.