## 2 Methodology--Related Works
### Smart Production Control and Service-Oriented Architectures
The fundamental idea of SOA was to design infrastructure around services rather than applications. Instead of designing and building entire software applications, programmers focus on the orchestration and the allocation of services. Services are small units of software that contain a certain functionality [63]. Since its emergence, SOA has been adopted by numerous other disciplines. In the context of this paper, the business context is the most important. Here, SOA can be understood as a set of services businesses offer partners, customers, or other members of the same organization [64]. In terms of a manufacturing system, this can be understood as follows: machines offer services (the transformation of goods/materials) according to the customer's needs. The customer (depending on the chosen granularity) can be the company's customer, a specific department, or a piece of material that needs to be transformed to become the desired product. The interaction between machines and material/customer orders can then be decided decentralized and situationally, depending on various factors like processing state, capacity utilization, or the setup of the machines. The allocation of machines and material/customer orders is consequently not planned in a centralized manner but rather decided situationally. Figure 5 illustrates the concept in the context of a completely digitized factory shop floor. After the customer order has been placed and processed, a manufacturing order is generated in the cloud. The specific order is then connected to the material (or rather, its digital twin) and a CPPS component is created. This component contains all necessary information about what transformations (services) are necessary and in what sequence. After the production order has been released, the part will \"negotiate\" its way through the production system. This happens by constantly communicating with the entire system or a subset of the machines regarding who can perform the next necessary task. Depending on the current state of affairs, the machines will estimate how much the transformation would cost. Based on this, the selection will be made until all necessary transformations have been performed. Following these explanations, the following requirements arise for a basic description logic for data within manufacturing companies about their use in production:  
* In order to be applicable in a real-life environment, existing data from ERP or MES systems must be integrated without too much effort. * New or altered data from a digitized shop floor (in part or fully) should be easily integrable (e.g., changed process times and altered maintenance intervals). * Changes in the manufacturing system (e.g., new machines and other resources) must be integrable without much effort. * The same applies to changes in the production program: adding new products or materials to the production system or removing expired ones must be easy and carried out with low effort. Figure 5: Schematic representation of an agent-based SOA planning and control logic (derived from [7]). * The logic must be applicable in and support the factory and technology planning processes. It must also work when it comes to operational production planning and control. * The logic or programs applying this logic must provide a low hurdle threshold for integrating implicit worker knowledge (e.g., the integration of new allocations of production resources and materials or manufacturing tasks). Independent of the supposed solution, none of the concepts and methodologies mentioned above offer a realistic solution for the abovementioned requirements. The question of how to design a system or a methodology in which the relevant pieces of data and information can be stored, used, and presented in a way that allows for self-sustainability but also uses the existing data sets has not been found so far. This is where the authors propose the following basic task logic to make a difference.