Isaca COBIT-Design-and-Implementation Exam - Topic 3 Question 36 Discussion

According to the COBIT 2019 Design Guide:

'When outsourcing is selected as the sourcing model, managing relationships with external vendors becomes a top governance and management priority to ensure service quality, compliance, and accountability.'

This makes APO08 Managed Relationships the essential management objective for ensuring outsourcing success. While security and performance are important, managing relationships is the core requirement in an outsourced model.