PushManagement is targeted at Server applications and relies on Methods defined in 7.10 to get a CertificateRequest which can be passed onto the CertificateManager. After the CertificateManager signs the Certificate the new Certificate is pushed to the Server with the UpdateCertificate Method.
The Administration Component may be part of the CertificateManager or a standalone utility that uses OPC UA to communicate with the CertificateManager (see 7.3 for a more complete description of the interactions required for this use case). The Configuration Database is used by the Server to persist its configuration information. The RegisterApplication Method (or internal equivalent) is assumed to have been called before the sequence in the diagram starts.
A similar process is used to renew certificates or to periodically update Trust List.
Security when using the PushManagement model requires an encrypted channel and a Client with access to the SecurityAdmin Role. For example, SecurityAdmin Role could be mapped to user credentials for an administrator or to a ApplicationInstance Certificate issued to a configuration tool. OPC 10000-21 defines a mechanism to install administrative Client Certificates into the Server TrustList.