# Advances in Multi-Process Hybrid Production Cells for Rapid Individualised Laser-Based Production
## 5 Conclusions

Table 1: Main outputs of HyProCell for each KPI related to the main objectives defined in the project. instead of pallets; automated probing cycles to establish thickness and flatness of substrate; in-line data analysis of build plate geometry; and adequate positioning of parts on substrates in accordance with production planning and risks of distortion. 3. The major challenge of integrating AM and subtractive machining in the current hybrid workflow is the need for a \"hybrid process-planning\" protocol for post-processing of AM parts that accounts for the varying processing nature of AM (material shrinkage, layer thickness, orientation, anisotropy, etc. ), machining (tool design, machining allowance, etc. ), and part-specific attributes (critical features and tolerance requirements). SLM pilot cell: (i) Integration of real machines in a hybrid AM cell is an effort which should receive further development attention, especially when such cells use legacy machines. The standardisation of OPC-UA and the use of the standard is still uncommon in both additive and subtractive machine tools. Since the implementation of all or some elements of the OPC-UA standard is left to the discretion of the manufacturers of PLCs, best practices, tutorials, and open \"code snippets\" are needed to boost their use. A platform for different PLCs from different manufacturers, where this \"integration-knowledge\" is stored, will facilitate the development of OPC-UA interfaces so that PLC programmers might gain more control, freedom, and speed in development. To make it easier for them, the tools to create this OPC-UA models must also be easy to operate and understand. (ii) A fast feedback loop between different system designers (monitoring tool, machine manufacturer, control device programmers, information model, MES, etc.) is crucial for a good product. Starting with an appropriate project platform can help a lot for the future. (iii) It is advantageous to use a constant/fixed part coordinate system, such as the pallet system, to seamlessly switch between additive, subtractive, and other operations. It is necessary to guarantee part accuracy and repeatability. Methods to define/create a part coordinate system in the hybrid AM workflow need to be considered from the beginning of the cell conception. Distortions during the AM process can cause differences of positioning compared to theoretical expectations, and this needs to be corrected by testing measurements in the machining machine. (iv) Reaching the best level of automation and integration in the SLM pilot cell would result in a significant reduction in downtime. This was demonstrated for each defined batch production scenario. LMD pilot cell: (i) The function of a combined machine for additive and subtractive machining is a highly focused one with a clear need. It must be clear that the required process relies on the functions available within such a machine type. Such functional combination is required for repair. Repair has a strong focus on adaptive machining as well, which makes measurement capabilities in the machine essential. The currently available measurement solutions in machine tools such as touch probes and laser line scanning sensors are accurate but slow; therefore, compromises between timeliness and accuracy must be made. (ii) The machine operator on the shop floor must be properly supported. Machine operators are usually focused on a single process. The combination of additive, adaptive, and subtractive machining with all their relations is very difficult for an operator to handle. The process needs--and this is essential--complete adaptation of the additive and subtractive tool paths for each individual part. Automated communication and exchange of data between the machine and connected CAM system ensures a fast and reliable process. (iii) In hybrid LMD workflows, the downtime associated with constant tool changes caused by switching between deposition and machining is a non-value adding step.