## 3 Implementation of the Decision Tree Algorithm  
The Industry 4.0 concept's evolution inevitably involves implementing new solutions based on IT systems for the entire design and production process. These systems often enable cooperation between different remote units with dispersed resources such as scientific units, companies, or production clusters. An essential role in implementing this concept is played by rapid prototyping, which allows us to create and develop entirely new ideas and modernize the existing ones. This form of production, based on incremental technologies, can be used both in the area of multi-series design, as well as in short-run production, or single elements, components, and prototypes. Considering various limitations resulting from the dispersion of design and production resources and crises, e.g., epidemics, the process of remote design and production can play a significant role. In cooperation with the Rzeszow University of Technology's scientific community, such a system was created in InfoSoftware Polska Ltd., Rzeszow, Poland. This system is called iS Rapid and enables the remote realization of the whole design and production process. This process consists of three essential areas: design and modeling, manufacturing, and quality control. Individual works within these areas can be realized in different ways. The CMMN model (case management model and notation) of rapid prototyping process scenarios is presented in Figure 1. In the design and modeling process within the iS Rapid system, one can distinguish the main activities of the main process: independent preparation of the model for 3D printing by the customer at his premises, development of such a model in a virtual environment available within the iS Rapid platform, as well as commissioning such a design task to specialized staff within the iS Rapid system. In the next stage of the design and production process (related to the module _E. Production method specification_ in the CMMN diagram, actually being a choice of 3D printing method), it is possible to create the target component within various incremental technologies: FFF (Fused Filament Fabrication), DLP (Digital Light Processing), SLA (Stereolithography), SLS (Selective Laser Sintering), PolyJet (Polymer Jetting), and CJP (ColorJet Printing). Of course, the choice of individual technologies is also connected with the possibility of choosing the right materials: ABS, PLA, PCABS, PET, TPU, Nylon, HIPS, PVA, PMM, light-curable resins, finely powdered metal alloy, polymer, ceramic powders, etc. On the other hand, in the case of the quality control stage (associated with the _H. Quality Control_ in the CMMN diagram), the customer has the possibility of remote surveillance using high-resolution cameras (standalone), use of a specialist engineer to assess the entire physical manufacturing process, or to assess the condition of an already manufactured component (specialist). There is a possibility of giving up such an option in the design-creation process (none). Figure 1: Case management model and notation (CMMN) model of the rapid prototyping process. This article examines how customers choose particular options at different stages of the design and production process and the consequence of the final decision related to purchasing such a remote prototyping service. Of course, such variables as design variant, manufacturing technology, and quality control variant are exploratory variables, and the purchase is a target variable. Table 1 shows sample cases--orders registered in the system. One can notice that case no. 1 was realized in its entirety. The customer ordered all service elements, including quality control, from a specialist available in the company. In the second case, however, we can see that the service was purchased (fully paid), but the service does not include, as one can see, quality control.