Automotive quality requirements and process capability in the production of electric motors

The progressive electrification of the worldwide vehicle fleet is leading to an increasing importance of electric motors in the automotive industry. Many automobile manufacturers therefore integrate the production of electric motors into their value chain and expand capacities to maintain the level of value creation and quality leadership. Process technologies necessary for the electric motor production are gradually replacing well-known process technologies in the automotive industry. While traditional process technologies are providing maximum process control regarding cycle times and reject rate (capable processes) within the framework of six sigma, process technologies of the electric motor production cannot keep up with the existing requirements of process control. For optimization, the stochastic elements of each incapable process must be identifiable. The objective of this paper is to present a method for identifying and evaluating process technologies of the electric motor production based on the process capability requirements of the automotive industry. It is shown that automotive production processes, which were deterministic, are facing high stochastic variations. In contrast to traditional production processes the output cannot be calculated in advance, but only retrospectively determined by intensive functional testing. Additionally, efficiency deficits occur through increased cycle times and a high reject rate. A ramp-up of production with finally capable processes and predictable process outputs is therefore complex, time-consuming and cost-intensive. Thus, this paper presents a model to identify needs for action in the process chain of electric motor production regarding predictability and process control.