Benjamin Haefner

Local order scheduling for mixed-model assembly lines in the aircraft manufacturing industry

Multi-variant products to be assembled on mixed-model assembly lines at locations within a production network need to be scheduled locally. Scheduling is a highly complex task especially if it simultaneously covers the assignment of orders, which are product variants to be assembled within a production period, to assembly lines as well as their sequencing on the lines. However, this is required if workers can flexibly fulfill tasks across stations of several lines and, thus, capacity of workers is shared among the lines. As this is the case for final assembly of the Airbus A320 Family, this paper introduces an optimization model for local order scheduling for mixed-model assembly lines covering both assignment to lines as well as sequencing. The model integrates the planning approaches mixed-model sequencing and level scheduling in order to minimize work overload in final assembly and to level material demand with regard to suppliers. The presented model is validated in the industrial application of the final assembly of the Airbus A320 Family. The results demonstrate significant improvement in terms of less work overload and a more even material demand compared to current planning.

Design for Testability for Micro-mechatronic Systems

The development and manufacturing of highly precise micro-mechatronic systems, such as MEMS applications, is a challenging task due to the complexity and variety of their manufacturing technologies, as well as their high quality requirements. Within the context of the product engineering process of micro-mechatronic systems, quality inspection by means of production measurement technology is a crucial factor. This paper presents a survey of the challenges regarding quality inspection of micro-mechatronic systems. Furthermore, a Design for Testability approach for these types of products is described and exemplary applications of its implementation are shown.