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 is possible to find downloadable forms that you can use as a starting point for your agreement with a 3pl service. 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. Web service level agreement template.