Developing a dynamic risk simulator for rotating equipment integrity management

Abstract

The aim of this thesis is to understand the existing relevant practices, processes, Norwegian regulations for rotating equipment and develop a simulator to model and simulate the lifetime of single-unit repairable systems subjected to age-related failures towards qualitatively visualising the financial, safety and environmental risks associated with varying periodic preventive maintenance intervals for two maintenance strategies, the minimal-repair periodic-overhaul strategy and the run-to-failure strategy. The simulator also provides quantitative estimates on the cost of maintenance, optimal maintenance interval and equipment availability for finite time horizon. The purpose of such a tool, the Dynamic Risk Simulator, is to serve as decision support to help the decision maker to value his/her options on proceeding with or delaying preventive maintenance.

The factors which affect selection of maintenance policies for equipment were identified and the equipment failure, repair and maintenance processes were mapped. This was used in the development of the underlying models and algorithm of the Dynamic Risk Simulator and the specifications for its input and output parameters were established. A proof-of-concept Dynamic Risk Simulator was built with a Graphical User Interface using the Microsoft Excel VBA language. The simulator has been partially validated with data provided by offshore operators through Apply Sørco AS. The limitation of the developed tool is that it cannot replace human judgement with regards to taking the final call on whether or not to postpone maintenance. The simulator provides quantitative and qualitative results and is reliant on the experience and insight of industry experts to take the most appropriate course of action.