Which term describes if a service is fit for use?

Serviceability refers to the contractual obligation of a third-party supplier to maintain a service or component, not the overall fitness-for-use concept.

Utility is the functionality offered by a service to meet a particular need - it describes 'fit for purpose,' not 'fit for use.'

Warranty is the ITIL term meaning a service is fit for use - it provides assurance that the service meets agreed requirements related to availability, capacity, continuity, and security. Utility describes what a service does (fit for purpose), while warranty describes how well it performs under agreed conditions. Together, utility and warranty create value for the customer.

Availability is one element that contributes to warranty, but it is not the overarching term that defines fitness for use.