A change management framework: managing the error variations in multi-stage machining processes

There are always changes in multistage machining processes (MMPs), which enable machining quality of process to fluctuate. At the same time, these changes contain some valuable information of MMPs, and they can be used to explore the characteristics of MMPs. In this paper, the concept of change management in the engineering change is introduced into MMPs to manage the error variation. A change management framework is established according to PDCA (plan-do-check-act) cycle. Under this framework, time-space characteristics of machining quality change are analyzed, and then a hierarchical control and management system with the aid of e-QC controller is presented. According to machining form feature of part, correlated relationship among different stages is firstly defined, and then quality control chain of MMPs is generated through mapping relationship between quality characteristics and process activities. Once some abnormal change occurs in MMPs, e-QC controller is used to manage these changes. At last, an example is used to verify the proposed methodology.