The MES umbrella organization has therefore developed the IIoT-capable, bidirectional open source MES interface DES4MES (Data Exchange Services for Manufacturing Execution Systems) based on OPC UA and presented it at the Hannover Messe 2018 . One of the members of the association, MPDV Mikrolab, is already systematically working on this. MPDV Mikrolab introduced the MES Hydra to the industry a service interface that aims to excel in particular with a high degree of interoperability . The REST-based (Representational State Transfer) MES has an explorative self-describing API (Application Programming Interface) and allows the calling of Hydra services through the http or https protocol. This also makes it possible to connect any existing software as well as self-developed software clients.