Determination of Machinability Considering Degradation of Accuracy Over Machine Tool Life Cycle

The emergence of financially and environmentally conscious manufacturing has resulted in a need for efficient process planning in today's manufacturing system. Process planning based on nominal machine tool specifications, limits predictive capabilities with regard to the final part quality. More efficient process plans can be achieved once an accurate machine tool capability profile has been defined. Machine tool capability profiles deliver up-to-date resource attributes such as availability, health and applicability into the process-planning stage. A manufacturing resource's health degrades continuously throughout its life cycle due to environmental factors, part wear, operator competence, etc. Identifying and compensating for these factors during process planning may alleviate material wastage and machining estimate production time and cost via decision-making mechanisms. In this paper, the STEP-NC Standard is used to represent a model of machining resources, including worktable, spindle and tool status during a machine tool's operational lifespan. A prototype of machine tool capability profile enabled process planning system is then presented and tested to highlight the advantages of this approach.