# Advances in Multi-Process Hybrid Production Cells for Rapid Individualised Laser-Based Production
## 1 Introduction  
Individualised production is the manufacturing of products or lots of parts that are uniquely differentiated from one another. It is an emerging trend which provides added value and distinction within high-value manufacturing: suppliers can provide more ad hoc competitive products (according to the customer's wishes) and deliver new services and localised functionalities (production on demand). Laser-based additive manufacturing (LBAM) [1] is well suited to individualised on-demand production due to its ability to transform digital designs directly into physical-complex products, particularly for small batch sizes. In recent years, metallic additive manufacturing (AM) has generated great industrial interest in different sectors [2] and has grown significantly, and hybrid AM (alternating additive material deposition and subtractive material removal) opens new possibilities in terms of flexibility and productivity in the automated production of net parts of high complexity and low cost [3]. The metal machine AM market is witnessing an emerging and critical time [4], but it is not yet competitive on a large scale, especially because additively manufactured parts are often more expensivethan those produced by conventional methods, and production speed is not as fast as promised [5]. Aside from the manufacturing time inherent in layer-by-layer material-laser interaction using additive processes, significant downtime is involved in the adjustment of machines from one batch to another, such as in the changing of materials, cooling of the part, preparation and extraction of the manufacturing platform, final extraction of powder in the part, etc. Additionally, the handling of parts still requires intervention by operators and other isolated processes. On the other hand, parts almost always require post-processing treatments to meet customer requirements: machining operations or surface treatments are required to meet surface quality specifications (irregular surface roughness, high requirements for the application, e.g., <1 \(\upmu\)m for parts subjected to fatigue) and dimensions in critical areas (areas with strong dependence on tolerance, mating surfaces), or part removal from the base plate is necessary and the supports must be eliminated from the part. This insight has motivated research into hybrid AM, a novel production approach combining additive manufacturing with other technologies [6]. This combination process is used to overcome the drawbacks of slow additive production processes by retaining the advantage of producing free-form parts without the need for moulds and forms. Some authors go in depth with new concepts for hybrid AM, combining not only subtractive and additive processes, but also the integration of assembly, forming, and measuring in an abstract concept called incremental manufacturing, which comprises robot-based and thus geometrically flexible step-by-step additive finalisation of prefabricated basic parts with a high build-up rate and, if needed, subsequent subtractive finishing of functional surfaces [7]. Additionally, there is improper integration of these post-processing and other conventional processes--subtractive as well as complementary (powder removal, heat treatment, surface finishing)--with LBAM (including part design and production planning), complicating product and process traceability. On the other hand, in LBAM related facilities, different workshops in the value chain use different software to optimise the manufacturing process, and each one \"thinks\" about its own process as an isolated manufacturing step, even when working in the same value chain.