## 3 Model Comparison  
A number of models and architectures, integrating manufacturing elements and human resources in the prototyping process, were used in the course of work on prototyping elements that preceded the development of the presented RDRP system model. Once again, it shall be emphasized that the discussed process of rapid prototyping is based on resources heterogeneous from the point of view of properties, i.e., the working environment is created by people and machines belonging to various entities, which have different properties. In the simplest, classical model, the integration of resources was based on sharing design files and human resources. In this approach, it was necessary to organize and coordinate team meetings and production work. This model is still used in many companies, but its main disadvantage is a very long period of project work. This is due to the need of synchronizing many people's work schedules and availability of resources of various entities for the project team. At the start of the process, the model's purpose was taken into consideration, but the team estimated the duration of prototype development to last for 100-150 days. For this reason, among other things, this model was not chosen as the targeted one for the ventilator production.  
In the second stage, the application of the cloud manufacturing (ubiquitous manufacturing) approach, described in [4, 5], was considered. The team already had some experience in this area, in particular in its use for the development of cyber-human systems (Figure 1). In systems of this type, the paradigm of cloud in the IaaS (Infrastructure as a Service) model known from computer solutions, researchers and engineers attempt to transfer to the environment of manufacturing machines, omitting the utterly different nature of the industrial environment. Difficulties in the implementation of this class of systems are recognized by multiple authors of scientific papers within this field, who jointly confirm the low interest in the direct implementation of this class of systems, even in the academic environment [4]. In one of the projects, related to the aviation industry, the team undertook the implementation of the idea of cloud manufacturing in the environment of several companies. Unfortunately, this class of system requires a very strong standardization of all processes, communication interfaces, types of project files, and IT management systems. The process of standardization and unification of access to systems' diverse ownership and properties takes a very long time and is extremely costly. The final cost and time needed for the preparation depends on the number of entities involved and the complexity of the structure of production machines. In fact, this model allows for the integration of resources in each of the stages indicated in Figure 1, although, due to the time of preparation works, it is applied in the case of static long-term cooperation between manufacturing entities. These entities may share resources with each other or make integrated resources available to external customers by offering them access in the cloud manufacturing model. Using this model in order to make resources available quickly and flexibly in the RDRP process is simply impossible. The team estimated that it would take approximately one year to integrate the resources in this model for ventilator manufacturing, which would include adequate staff training.  
Table 1 illustrates the comparison of the proposed model with the classical model and the cloud computing model from the point of view of applying it to the creation of RDRP systems. The comparison assumes that the basic architecture of the system, built on the basis of a given model, has already been implemented and a new group and new resources are being created as part of the work.