Risk-based decision-making for the management of structural assets.

This thesis investigates the benefitof risk-baseddecisionmethodsinengineeringdecisions. A thorough literaturereviewidentified the majorissues andlimitations incurrent methods. Consequently a more comprehensive model wasdeveloped to accountfor the complexities of reallife decision-making. Theenhancements introduced to themodelinclude identifyingand evaluating stakeholderinfluences, decisionobjectives,criteria and preferencesbetweencriteria anddecisionoutcomes.Monitoringandcontrollingimportantparametersduring implementation isalsoincluded to ensureobjectives are met and risks controlled.Toolsand techniques wereidentified to supportdecision-makingwithin the new model.Theresearchfocusesonhowavailabletechniques can improveengineering decision-making.Themodel was applied to fourcase studies analysing reallife, "live" decisionproblemsin bridgemanagement and pipeline management. Theseconfirmed the relevance andimportance of the model enhancements. Thepracticality of the methods, their benefitsand limitationswere evaluated such that the proposed model was enhanced further. Theenhanced model was shown to bringenhanced understanding to allfourcase studies andmade the decisionsmore rational, thorough and auditable.The fifthcase studyreviewedhowunsupporteddecisionsare currently made within the sponsoringcompany. This involvedadetailed desktop analysis of past projects and interviewswithsenior engineers and providedfurtherevidence, which emphasised the value of usingthe decision model.Generalguidelines weredeveloped basedon the case study experiences to help thedecision-maker identify the levelof analysis requiredfor different types ofdecisionproblems. These weredefinedas applicability matrices.The benefitof using a thirdpartyfacilitator ineach of the case studies wasidentified in terms of the roles ofleader,liaison, disseminator, spokesman anddisturbance handler. The balance between thesefiveroles through the stages of the decision process wasfound to be important to ensurethe facilitator does notdominate the decision.