TABLE OF CONTENTS Two case studies will demonstrate how the business-centered maintenance approach can assist the reviewing of maintenance strategy for the particular case of an equipment fleet. The first of the studies will also show how a mining operation, using such a fleet, can be modelled as a process flow.
MAXCOAL Ltd, a coal extraction business, ran two underground mines and an adjacent open-cast mine, as outlined in Figure 11-1. Emphasised in the diagram is the open-cast operation, which started with the stripping and removal of the overburden (the soil and rock above the coal seam) using drilling, explosives and a dragline. Coal from the exposed seam (which was some metres thick) was then extracted and loaded into trucks for haulage to the preparation plant, where it was firstly crushed and then washed and graded before finally being conveyed to a nearby rail head for transportation. There were a number of points of interstage storage and also a final product storage, which gave operational flexibility to each individual process and also to the activity as a whole.
The main feature was that the process depended to a large extent on the performance of small fleets of diesel-powered equipment. For example, five frontend loaders for the mining operations and eight large dump trucks for the haulage. (Other mobile equipment included dozers, scrapers, graders, drills, etc.) It is this equipment rather than the fixed or semi-fixed units such as coal washing plant,...
