Battle of the Philosophies : Comparing time-based and condition-based maintenance philosophies

Abstract

The objective of this thesis was to compare two different maintenance philosophies. This was done from the point of view of a tugboat-operating shipbroker, interested in the useful lifetime of the propulsion thrusters and the economic effects which both maintenance philosophy candidates would have on the maintenance plans on a strictly economical level. The different effects they would have on the future maintenance plans and budgets were compared, as well as the possibilities they have detecting forthcoming machinery failures before the failures would get severe. The study used both quantitative and qualitative approach due to the still rather novel status of a 5th generation maintenance programs, but also the scientific approach based on the documented and more theoretical studies of renowned maintenance specialists was utilized.

The results, gathered from real-life experience and theoretical studies, pointed in the same direction: condition-based monitoring is the most useful condition maintenance philosophy when the machine under surveillance is critical for the vessel or process. The results can be seen viable not just in the realm of the maritime industry, but also in a broader context.

This thesis was written for a Finnish tugboat company, which has decided to stay unnamed. Thus, the official recipient of the thesis will be Kongsberg Maritime Finland Oy.