Abstract
Changeability is one major goal of Industrie 4.0. Existing production architectures limit changeability, because programmable logic controllers (PLC) that are responsible for the execution of real-time production steps also define the order of production steps that are executed for every product. PLC programming therefore implicitly defines the production process. Consequently, any change of a production process requires changes in PLC code, causes potential side effects due to unknown controller dependencies, and requires extensive testing. We propose a service-based architecture approach that encapsulates production steps into re-useable services. Production cells invoke services, and comparable to multi-agent systems autonomously decide about optimal service invocations based on shared information. In this article, we outline our service-based architecture concept and describe a use-case that illustrates the decentral organization of production systems and the cooperative optimization of production steps.