Careful planning and negotiation between the provider and the customer is necessary when defining service credits in an SLA. To achieve this, identify the key service level objectives and metrics that are relevant, measurable, and achievable for the IT services in scope. These should reflect the customer's business needs and priorities, as well as the provider's capabilities and constraints. Additionally, determine the service level targets and thresholds for each SLO and metric, as well as how they will be measured, monitored, reported, and verified. The formula for the service credit should be simple, fair, and proportional to the impact of the provider's performance on the customer's business value. Furthermore, establish the service credit conditions and exceptions which should include the frequency, duration, timing of application, and process for claiming, disputing, and settling service credits. Lastly, exceptions should include events or circumstances that are beyond the provider's control or responsibility that may affect their performance or service credit calculation.