Managing risks to structures

Abstract

Structural engineering has changed markedly over the last decades, creating new challenges and new opportunities. Consequently, structural engineers are widening their thinking from just technical issues to the effects of other matters on the risks to their structures. In particular there is a need to find better methods for integrating hard and soft risks. Hard systems are physical and technical matters traditionally dealt with by engineering science. Soft systems involve people and include matters traditionally dealt with by engineering management. In order to make improvements, engineers have to combine good-quality evidence from disparate sources, both technical and from wider issues. The current paper demonstrates how disparate evidence can be measured and combined using interval probabilities drawn as colourful ‘Italian flag’ indicators of risk. Process models are used to map the progress of projects. An Italian flag is associated with each process to indicate the level of dependability, based on all the information available at the time, that the process will be successful, which is to reach the stated objectives. A new method of pairwise combinations is described and used to calculate the flags through the entire process model. An example of the procurement of a building is used to illustrate the method.