Where should the following information be stored? 1. The experience of staff 2. Records of user behaviour 3. Supplier's abilities and requirements 4. User skill levels

The forward schedule of change records approved and planned changes over time, not knowledge about staff, users, or suppliers.

The service portfolio documents services across their full lifecycle from pipeline to retirement, not human or behavioural knowledge.

The CMDB stores configuration items (CIs) and their relationships and attributes, not human knowledge, staff experience, or behavioural records.

The SKMS is the broadest knowledge repository in ITIL, designed to capture and store all organizational knowledge relevant to service management - including staff experience, records of user behaviour, supplier abilities and requirements, and user skill levels. It encompasses subsystems like the CMS and CMDB, making it the only option capable of holding all four types of listed information.