Techno-Economic Feasibility Assessment of Life Extension Decision for Safety Critical Assets

Life extension is one of the major end-of-life decisions in management of the industrial assets which must be made based on all information gathered from system operation and maintenance to ensure that the process is feasible. Most of the existing life extension feasibility assessment models are restricted solely to either “technical” or “economic” considerations, which may lead to inaccurate conclusion or misleading recommendations. In this paper, a techno-economic feasibility assessment framework is developed for life extension decision-making of safety critical assets. All aspects of data collection and review, screening and prioritization of safety critical assets, condition assessment, estimation of remaining useful life and risk analysis are incorporated in the technical assessment. A cost-benefit analysis is also applied to calculate all the costs and benefits of a life extension programme. The decision to qualify an asset for continuous operation beyond its service life is made based on a life extension index which is calculated by combining two indexes of equipment health condition and economic added-value derived respectively from the technical and economic assessments. For the purpose of clarity, the proposed model is applied to a water deluge system on an offshore oil platform.