A service level agreement, often abbreviated as sla, is used in it and professional services to. Web in logistics, a service level agreement is a contract between a business and a logistics partner that outlines the services to be provided and the performance level. It generally contains standard information that won’t change between partnerships. Web specify the service that the 3pl will provide; Web service level agreement (sla) is a documented agreement between a service provider and a customer that identifies both the services required and the expected level of service.