*5.2. Openness and Interoperability*

A one-stop platform for the provision and enactment of services and goods of a M2X ecosystem is desirable instead of a manufacturer-focused platform with deliberately forced, or functional lock-ins that lead to the formation of self-contained data and service silos such as Tesla, Google, or Amazon. As suggested in [1], interoperability allows for the exploitation of economies of scale and increased efficiency. At the same time, an interoperable blockchain ecosystem can be operated as a joint venture of various stakeholders and include built-in e-governance mechanisms, thereby constituting a neutral territory for all stakeholders [1,52]. A smart-contract driven M2X platform and its corresponding ecosystem not only enable an interoperable platform for M2X entities, but also further reduces dependency on intermediaries [53].

The technical implementation is realized by so-called relay chains as introduced by Polkadot [52] that provide communication interfaces for different heterogeneous blockchain platforms to interact with each other and subsequently, allow for a blockchain-agnostic, highly-automated, globally-available orchestration and choreography of heterogeneous socio-technical systems. Thus, specific manufacturers, or service-provider specific functionalities may also be accessible outside their own platform.
