Within the aviation industry analysis of wear debris particles recovered from magnetic plugs and lubricating fluids is an essential condition monitoring tool. However, in large organisations, high staff turnover in remote work environments often leaves dangerous gaps in on-site support and background knowledge. The current work develops interactive software for wear debris particle classification, root cause diagnosis and serviceability prognostics. During the research several hundred wear debris particle images were collected, analysed and classified by a number of experts. At each stage of the analysis the experts were questioned about the knowledge and experience used to make their diagnoses and prognoses. The end result is an extensive knowledge base representing the combined expertise of a number of highly trained engineers, each with decades of hands-on experience. Access to this knowledge base is provided at each stage of interaction with the software, as automatically generated expert-guidance notes, which support the end user in their decision making by letting them know exactly what the expert would be thinking at that point in the analysis. This helps to correct systematic misconceptions, resolve ambiguities and offers appropriate alternative diagnostic choices. The use of brief, contextual pieces of information means that facts and concepts are more easily understood and remembered. The software uses the nomenclature of, and is compliant with, the ‘ASTM D7684-11 standard guide for microscopic characterisation of particles from in-service lubricants’. It allows the end user to integrate standardised particle analysis into the daily work flow, whilst acquiring knowledge and skills in a practical setting.