Progressive cavity pumps are used in the transportion of slurries. The pumping element consists of a single helical rotor, which intermeshes with a double helical resilient stator, to create the moving cavities that transport the slurry. Both components suffer from weaL at different rates, due to relative sliding movement of the rotor to the stator, and the presence of the abrasives carried within the slurry. for a pump manufacturer to remain active in the market they must provide the customer with optimised material selection, for both wearing parts, at a competitive price. Wear is not an intrinsic material property and its value is dependent upon the conditions within each individual tribological system. In order to improve or optimise the wear life of a system, it is first vital to understand the complexity of the mechanisms that generate the material loss. This thesis achieves this goal, with specific reference to a pumping system, by analysing the wear mechanisms of the pumping element components in progressive cavity pumps and evaluating how the wear severity changes with the system parameters. The in-depth study has enabled a new wear model to be proposed which describes how the behaviour of the abrasive particles contribute to the wearing process, in the pumping element of a progressive cavity pump. Hard particle laboratory wear tests were reviewed and assessed to determine their suitability for assessing the wear performance of rotor and stator materials. It was concluded that no one standard laboratory test was suitable and recommendations are given for two tribometers which specifically meet the tribological needs of the pumping system