Feature-based process planning for environmentally conscious machining – Part 1: microplanning

Abstract Process planning in environmentally conscious machining involves a multi-objective analysis of manufacturing dimensions that include production rate, quality, process energy and mass of waste streams generated by the process. While there has been a body of work developed in life cycle analysis, one of the critical issues limiting environmental analyses is the material and geometric complexity of engineered components. In this paper a formalized approach towards integrating environmental factors in process planning is presented, which incrementally evaluates part designs through an aggregation of features. Process planning is divided into two phases, micro and macroplanning. In microplanning, process, parameters, tooling and cutting fluids are selected for the individual features, while in macroplanning interactions between features are examined. Microplanning is the focus of this paper where predictive process models are used to obtain process level inventory of process energy, machining time, mass of waste streams (primary scrap and secondary catalysts) and quality parameters. The mass of waste streams are then evaluated for their environmental impact based on a health hazard scoring index. The Microplanning algorithm integrates these dimensions in an optimization framework to make robust process planning decisions at the feature level. A case study of a machined part is presented to illustrate the microplanning methodology.