Quality performance analysis for the whole product family with multiple characteristics: apply the cooling pump as an example

Abstract

The function of cooling pump is to release and cool off the heat caused by the operation process of cutting tools and their related cutting materials, through cooling oil cycle effects, therefore to avoid damage to the tools and their materials. Three quality characteristics of cooling pump: function, safety and energy-saving, must meet the requirement of CNS-5703 product safety standard. Through multi-process capability analysis chart, we can improve and control those poor qualities of various pump products. Process Capability Indices (PCIs) are powerful tools to study the process ability for manufacturing product that meets specifications. A larger process capability index implies a higher process yield, and lower expected process loss. In the past references based on Cp , Cpu , Cpl , and Cps , the approach of this research is to develop one integrated process capability analysis that can precisely measure product with larger-the-better and smaller-the-better multi-process, and nominal-the-best characteristics. However, Cps suffers from the weakness of being unable to reflect process biased. Therefore, the paper selects index Cpn to replace Cps . Meanwhile, an integrated PCI for the whole pump product family is proposed, and the relationship between the PCI and process yield is described. We could find and improve unusual quality of the pump product family by multi-process capability analysis chart.