On the use of acceptable risk constraints in resource allocation domains

The author seeks to bring some clarity and perspective on the use of acceptable risk by reporting on a specific case study in which it was used. He describes an application where acceptable risk is used in planning the replacement of cast iron and steel pipe sections in a natural gas distribution system. The application reveals some practical lessons, including, the need to frame risk constraints in terms of events where there is operating experience and the need to work within a risk management framework which is integrated with respect to the total system being managed