An integrated cost model for metal cutting operations based on engagement time and a cost breakdown approach

In all manufacturing processes, it is important to determine the costs and their distribution between different sequential processing steps. A cost equation based directly on the losses during manufacturing, such as rejection rate, stops and waste of workpiece materials, also provides a valuable aid in giving priority to various development activities and investments. The present work concerns how a cost model presented earlier for calculating part costs can be developed to describe part costs as a function of the cutting data and tool life time T selected. This enables a tool life model to be a directly integrated into the cost model by use of tool engagement time. The model presented also takes into account the part costs for scrap incurred in connection with forced tool changes. Examples are also given of how the model developed can be used in the economic evaluation of various cutting tools and workpiece materials.