Prevention of accidents as low as possible is a very board terms.... it, of course, includes what Cicero said... Identification of hazards, risk assessment and risk control. If I elaborate it right here, severial pages are not adequate... hehe.... also dont neglect 'as low as possible' which is something like as far as reasonably practicable... it is a risk control theory... ALARP... if you are interested, you can search this philosophy on internet. This philosophy has been widely adopted in developed countries.