The scope of work and the delivery model for the run is established during the pre-sales phase depending on customer’s needs. The present chapter establishes guidelines which will be adjusted depending on the customer scope of work.

The Level 3 are the experts about the service component. They are the most knowledgeable to troubleshoot and resolve an incident on the service component. They implement the observability, the alerting and the procedures for troubleshooting, the backup and the procedure for repairing the service component. They validate the procedures and handoff those procedures to the Level 2. They troubleshoot incidents and problems in last resort when the Level 2 cannot fix it.

For a Business Functions of the Application, the Level 3 is typically customer’s responsibility: Customer’s development and test teams – or 3^rd party teams subcontracted by the customer – who have coded, deployed and tested the Business Application and the Business Function. Customer may contract support to the software editor of the Business Application and Business Function.

Customer can subscribe SRE and Cloud Expert Services from OBS to strengthen the team.

Would the customer request OBS to take responsibility for the Level 3 of a 3^rd party Business Application (with a potential partner for 3^rd party application maintenance), a specific scope of work and agreement shall be established.

For the IaaS, PaaS, OS, Database, it is typical that the customer may rely on OBS to take care of the Level 3. However, other patterns are possible and can be discussed and established during the presale phase.

Here is an example of responsibility pattern for a project