Backlog Management

Control of backlog is fundamental to successful management of the maintenance function and thereby to realization of reliability. It must be held within manageable control limits by preserving a balance between resources and workload.
Backlog is defined as the net workload, measured in labor-hours, requested but not yet completed. Another definition is that the backlog is all identified work remaining to be performed. If a job has been started, only the portion of labor-hours still to be completed remains in quantified backlog.
Some of the jobs in backlog are delinquent in terms of promise date, but most are not delinquent. Being part of backlog does not connote delinquency.

Maintenance work is continuously created over time as:

·        Equipment is utilized and reliability diminishes
·        Facilities are exposed to weather and usage
·        PM/PdM inspections and other routines come due
·        Operational processes are altered or replaced
Planning for Maintenance/Reliability Excellence begins with Macro-Planning, which is perpetual balancing of maintenance resources with maintenance workload. If balance is not preserved between these two variables, the operation cannot achieve reliability.

Source:
Don Nyman
Joel Levitt
Maintenance Planning, Coordination and Scheduling Second Edition Industrial Press New York p69