Best-effort service level

All maintenance and support providers should have a service level agreement (SLA) with a customer but sometimes a best-effort service level is advisable to cover the times when through no fault of the service provider, the SLA cannot be met, or, the service level requires variation. Failure to comply with service levels can have many causes. It could be lack of spare parts or skilled engineers, or physical or weather restrictions, such as cancelled ferry crossings or flights, which form part of the trip to a site.