Change of messages and/or the structure of the reference file

The messages are maintained within the domain. Any involved stakeholder (RU, IM, AB, SM) can put the request for a change (new, alteration, deletion of a message) to the technical services management group. It has to consult the relevant expert working groups on the need of that change with 2 months notice. The working group can reject, ask for clarifications and give recommendations, eventually following an impact analysis within a given timeframe. If approved, a migration strategy has to be developed as well. On recommendation of the working groups the entity asks the Supervisory Board for confirmation. The entity publishes the changed messages and the migration plan soon after that confirmation and puts it into the ERA CCM according to chapter 7 of both TAP and TAF TSI. The message can be used according to that migration plan or on bilateral agreement. For: • optional change to existing specifications – information to Supervisory Board is sufficient • mandatory change to existing specifications and new specifications: Any stakeholder gives a request with justification for the change to the entity. The entity, together with the relevant SMG, creates a workplan. This plan is also used to inform the stakeholders in order to allow experts to be sent to working groups. Work is done by the WG following the approval of the workplan by the Supervisory Board. The result of the WG needs to be approved by the SB as well and is published subsequently. Change of message can only be once per year on a given date. Migration plan needs to allow companies to implement it (communication of change at least 1 year before usage). A migration plan should be proposed by the WG, including a minimum period in which the change is optional and a time from which the change is mandatory. The WG of the TAF and TAP governance entity should take into account both business and IT needs.