How to Write Service Level Agreements That Actually Work?

1. Start With Business Needs

One common mistake is setting service targets based on what the IT team can deliver rather than what the business needs.

For each service, identify which business activities depend on it and what happens if the service becomes unavailable.

For example, a payroll system being unavailable for four hours on a normal Tuesday may have little impact. However, the same downtime during salary processing can cause serious problems.

Service targets should reflect the actual business impact. This helps organisations avoid targets that are either too costly or too weak to meet business needs.

2. Separate Availability From Response Time

Availability and responsiveness are two different commitments, but organisations often treat them as the same.

Availability refers to whether a service is working and accessible during the agreed service hours. The SLA should clearly explain what counts as downtime. For example, does slow performance count as downtime? What happens if the service is unavailable at only one office?

Responsiveness refers to how quickly the support team responds to an issue and resolves it. The SLA should define response and resolution targets for each priority level.

A service may meet its availability target but still have incidents that take three days to resolve. Similarly, a support team may respond quickly while the service continues to experience frequent downtime.

Both areas need separate and clearly defined targets.

3. Define Priority Based on Impact and Urgency

Incident priority should be based on the impact on the business and how quickly the issue needs to be resolved. It should not depend only on the person raising the ticket.

Impact means how much the issue affects business operations, users, or services.

Urgency means how quickly the issue needs attention to prevent further problems.

Organisations should create and share a priority matrix so everyone follows the same rules. They should also specify who can change a priority and under what circumstances.

Without clear rules, the priority may be decided by whoever follows up most aggressively rather than by the actual importance of the issue.

4. Focus on Resolution, Not Just Response

A quick response does not always mean the problem has been solved.

For example, acknowledging a support ticket within 15 minutes may meet the response target, but it does not help much if the customer has to wait several days for a solution.

SLAs should include resolution targets for different priority levels, along with response targets.

If resolving an issue depends on a third-party provider, the agreement should explain how this dependency will be managed and how the third party's time will be considered when measuring performance.

This helps avoid confusion and disagreements later.

5. Clearly Explain How Performance Will Be Measured

Many SLA disputes happen because the measurement rules are unclear.

The agreement should specify:

• The service hours during which targets apply.

• Whether the measurement clock pauses while waiting for information from the customer.

• How pauses and delays are recorded.

• What counts as a resolved incident and what counts as a temporary workaround.

• The reporting period used to calculate performance.

• How partial reporting periods are handled.

Clear measurement rules help both parties understand how performance is calculated and reduce disagreements.

6. Agree on the SLA With the Customer

An SLA should be discussed and agreed upon by the service provider and the customer, not simply published as an internal document.

ISO 20000-1 places importance on agreed service levels and reviewing them with customers at planned intervals. Organisations should maintain evidence of these agreements and reviews.

For example, an SLA published on an internal portal without any discussion or agreement with the customer may not demonstrate that both parties understand and accept the commitments.

This is particularly important for internal IT teams that provide services to other departments within the same organisation.

7. Include Customer Responsibilities

Successful service delivery depends on both the service provider and the customer.

Customers may need to provide system access, share accurate information, make timely decisions, approve changes, and raise service requests through the correct process.

These responsibilities should be clearly stated in the SLA.

When only the service provider's obligations are documented, it becomes difficult to manage delays caused by missing information, approvals, or other customer-related dependencies.

A balanced SLA defines the responsibilities of both parties.

8. Review and Update the SLA Regularly

Business requirements, technology, and service expectations change over time. An SLA created two years ago may no longer reflect current business needs.

Organisations should establish a review schedule and assess the agreement using actual service performance data.

If a target has been consistently achieved by a large margin for a long period, it may be worth checking whether the target is appropriate and whether resources are being used efficiently.

If a target is regularly missed, the organisation should investigate the reasons. It may need to improve its service capabilities, allocate additional resources, or revise the target where justified and agreed upon.

Regular reviews help keep SLAs realistic, useful, and aligned with business priorities.

Common SLA Weaknesses to Avoid

1. Setting targets based on internal capabilities instead of business requirements.

2. Defining availability without explaining what counts as downtime.

3. Measuring response time without setting resolution targets.

4. Assigning priorities without considering impact and urgency.

5. Leaving measurement rules unclear.

6. Publishing SLAs without formally agreeing on them with customers.

7. Failing to document customer responsibilities.

8. Not reviewing SLAs against actual service performance.

Conclusion

A well-written SLA should do more than fulfil a compliance requirement. It should set clear expectations, define measurable targets, establish responsibilities, and help both parties understand how service performance will be managed.

By aligning service levels with business needs, defining measurement rules, and reviewing performance regularly, organisations can make their SLAs more practical and effective.