Perception and acceptability of risk in engineering projects

No engineering project can be designed to accommodate every possible (however unlikely) condition that can be imposed on it. Economics dictate that a selected number of criteria be used that represent a realistic scope of possible design requirements. By necessity, those conditions that will in all likelihood not occur within the lifetime of the facility are excluded. Various design codes assist the designer in selecting these design criteria. However, in many complex projects, alternative approaches are needed to identify those hazards that need to be designed for. Risk analysis provides the tools for assessing the impact of different events on the environment and the society. This paper briefly discusses various factors that need to be considered in setting maximum allowable risk levels for a project. These include the public's perception of risk, the benefits derived from the project, the cost of reducing the risk and comparable levels of risk in related industries or similar projects. Dit is uit die aard van die saak onrnoontlik om vir alle moontlike toestande voorsiening te maak in die ontwerp van 'n projek. Ekonomiese oorwegings verels dat slegs daardie omstandighede wat redelik geredelik sal voorkom tydens die leeftyd van die projek, inaggeneem sal word. Hoogs onwaarskynlike gevalle word noodwendig nie oorweeg nie. Verskeie ontwerpkodes word deur ingenieurs vir hierdie doel gebruik. In meer kompiekse projekte is dit egter nodig om alternatiewe metodes te gebruik om te besluit oor die toepaslike gevare of bedreigings waarvoor ontwerp moet word. Risiko-analises is spesifiek geskik om verskillende impakte op die omgewing en die gemeenskap met mekaar te vergelyk en te evalueer. Hierdie verhandeling bespreek kortliks metodes waarmee aanvaarbare risikovlakke vir projekte vasgestel kan word. Aspekte wat oorweeg behoort te word, sluit in die publiek se siening van risiko, die voordele wat hulle daaruit kan put, die koste verbonde aan die vermindering van die risikovlak, en vergelykbare risiko's in ander dissiplines of swrtgelyke projekte.