Nesting and Scheduling in Additive Manufacturing

Today technologies of additive manufacturing or 3D printing are not only used for the creation of prototypes in the product development process, but are also applied in the production of marketable products in a variety of industries. The ability to produce different products or components simultaneously on a 3D printer has also led to the development of new business models, such as "Factory-as-a-Service". This development makes efficient planning of the workflows within the manufacturing process indispensable in order to make the best possible use of the resources employed and to meet the requirements of the customers.

The dissertation focuses on the optimization of the placement of components in the available build space, the associated definition of component batches and the allocation or sequencing of the resulting batches on the available 3D printers. The optimization should take into account both the efficient use of resources and customer-oriented objectives, such as on-time delivery. Due to the interplay of sub-problems in the field of additive manufacturing, the problem represents a novel combined planning problem in the area of scheduling problems. Accordingly, within the scope of the dissertation project, the following aspects, among others, are to be considered and investigated with respect to the planning of additive manufacturing:

• Nesting: In order to group the components to be processed in batches, the arrangement of the components in the available installation space must be optimized. Depending on the technology considered, two-dimensional and three-dimensional cases can be distinguished.
• Scheduling: The batches are scheduled on the existing 3D printers. However, not only the printers themselves, but also following process steps must be taken into account in the planning, since these take up a large proportion of the processing time required. Hence, the resulting problem can be described as a Flow Shop Problem with batch processing.