Applying the functional system interaction process at ESS

The European Spallation Source ERIC is being built in Lund, Sweden to complement the existing neutron sources in Europe and worldwide. ESS will be the brightest neutron source ever built upon completion and aims to have an availability of 95% during steady state operations. The purpose of Machine Protection at ESS is to protect the equipment in order to support the high availability. Due to the distributed nature of Machine Protection numerous design teams are involved to implement Protection Functions. The Machine Protection development at ESS follows the Functional Protection lifecycle for System-of-Systems developed at the facility. This paper focuses on the application of the Functional System Interaction Process part of the Functional Protection method. To obtain the system interaction model, behavioural requirements and allocate Protection Functions, System Interaction Use Case workshops are held. The feasibility of different system architectures and protection function implementations are discussed and simulated by going through foreseen operational sequences, use cases. The different architectures and use cases are documented using Enterprise Architect