AMC1 ATM/ANS.OR.A.045(e) Changes to the functional system

• ED Decision 2017/001/R found in: ATM/ANS Provision of Services (2017/373) (Feb 2023)

AMC1 ATM/ANS.OR.A.045(e) Changes to the functional system ED Decision 2017/001/R CHANGES AFFECTING MULTIPLE SERVICE PROVIDERS — OVERARCHING SAFETY ARGUMENT A change as defined in [ATM/ANS.OR.A.045(e)](#_DxCrossRefBm1726554913) may involve more than one service provider changing their functional systems. In this case, the change will consist of a set of changes to different ATM/ANS functional systems or their context. However, no matter how many individual changes to service providers’ functional systems are part of the change, they should be coordinated. An overarching safety argument, coherent with the arguments of the individual changes, that claims the complete change is safe should be provided. AMC1 ATM/ANS.OR.A.045(e) Changes to the functional system ED Decision 2017/001/R CHANGES AFFECTING MULTIPLE SERVICE PROVIDERS — OVERARCHING SAFETY ARGUMENT A change as defined in [ATM/ANS.OR.A.045(e)](#_DxCrossRefBm647742061) may involve more than one service provider changing their functional systems. In this case, the change will consist of a set of changes to different ATM/ANS functional systems or their context. However, no matter how many individual changes to service providers’ functional systems are part of the change, they should be coordinated. An overarching safety argument, coherent with the arguments of the individual changes, that claims the complete change is safe should be provided.