The service class name where the job is to run is configured in lsb.serviceclasses. If the SLA does not exist or the user is not a member of the service class, the job is rejected.
If the SLA is not active or the guarantee SLA has used all guaranteed resources, LSF schedules jobs without enforcing any service-level goals. Jobs will flow through queues following queue priorities even if they are submitted with -sla, and will not make use of any guaranteed resources.
bsub -W 15 -sla Duncan sleep 100submits the UNIX command sleep together with its argument 100 as a job to the service class named Duncan.