Service Level Agreements and Service Level Management
Agreements versus targets versus internal contracts
Service level management (SLM) is the practice of setting clear business-based targets for service levels and ensuring delivery against them. An SLA is an agreement between a provider and a customer that is documented and describes the service, the expected service levels, and the responsibilities of both parties.
Distinguish carefully - this is the most common exam trap:
- SLA (service level agreement) - between the service provider and its customer.
- SLO (service level objective) - a measurable target within an agreement, e.g. an availability objective.
- OLA (operational level agreement) - an internal agreement between parts of the same organization that support the SLA.
- UC (underpinning contract) - an agreement with an external supplier that supports delivery.
Common SLA structures are service-based (one SLA per service, regardless of customer), customer-based (one SLA per customer group, whatever the service) and multi-level (corporate, customer and service levels combined). SLAs should be business-based, not technically driven; SLM also conducts service reviews and monitors customer satisfaction.
Worked example: a cloud service promises 99.9% monthly availability to the customer (SLA). Internally, the network team commits to 99.95% to the service owner (OLA). The data-centre supplier contracts for 99.95% uptime (UC). The availability target of 99.9% is the SLO. Three parties, three instruments - questions swap them.
Traps: calling an internal agreement an SLA; assuming a supplier contract is an OLA; thinking an SLA must appear as a formal signed document (agreements are documented, but the practice is broader); treating SLAs as a way to penalise people rather than manage service; ignoring that SLM includes ongoing review, not just signing.
Rule of thumb: ask who is on each side? Same organization → OLA. External supplier → UC. Customer → SLA.