Conventional milling into CNC machine tool remanufacturing: Sustainability modeling

Abstract

Aims: Sustainability modeling for conventional milling into CNC machine tool remanufacturing-upgrading. Study design: Remanufacturing-upgrading of conventional milling into CNC machine in its mechanical part, it is merely traditional remanufacturing process of conventional milling where gearbox can be eliminated due to use of motorized axes. Lead screws can be replaced with motorized ball screws. Heavy parts of machine bed such column, knee and saddle are reused. A group of criteria are selected to conduct comprehensive sustainability assessment of remanufacturing-upgrading process include: 1. Remanufacturing cost: It is the cost of milling remanufacturing into CNC machine. 2. Remanufacturing time: It is the duration of time required for milling remanufacturing into CNC machine. 3. Accuracy: It is an expected technical performance of remanufactured milling into CNC machine. 4. Reliability: It is an expected technical performance of remanufactured milling into CNC machine. 5. Processing efficiency: It is the man-hour based productivity efficiency of a remanufactured milling into CNC machine. 6. Processing range: It is the flexibility of remanufactured machine tool into CNC machine. 7. Ergonomics: It is the interaction among operator, remanufactured milling into CNC machine tool and other system unit through the cell of manufacturing. Conventional machine tool into CNC machine remanufacturing-upgrading experience is used to project the suitable literature comparatively to construct sustainability assessment model. Sustainability assessment models in field of remanufacturing-upgrading are reviewed and modified to accommodate new changes that accompany the current case study.
 Place and Duration of Study: Middle Technical University, Institute of Technology-Baghdad, Mechanical Techniques Department, between February 2020 and July 2020. Methodology: Literature survey in area of remanufacturing assessment and remanufacturing sustainability assessment. Comparative literature based assessment application. Classification of literature sample. Re-representation of discussions and conclusions. Graphical representation of results. Isolation of criteria. Case study definition. Weighting of criteria. Triangular fuzzication of criteria. Weighting of satisfaction. Global weights calculation. Sustainability Index weight calculation. Results: Summation of sub-sustainabilities index weights is within limit of consistency. Environmental sustainability literature is predominated to be followed by economic and technical sustainbilities literature. Conclusion: Economic, environmental and social sub-sustainabilities are of good performances and directed toward sustainability. Social and management sustainability are interlinked and require more studies to be directed toward sustainability.