One of the key responsibilities of any maintenance organization is to make sure that necessary work gets done in a timely fashion. One of the best ways to do this is to ensure that the available resources are balanced with the amount of work that has to be performed. We do this by measuring and monitoring backlog - that amount of maintenance work that has been identified but not yet executed.
Backlog is usually reported as the number of "crew-weeks" of work. It is calculated by dividing the hours of all work in the backlog by the crew's capacity to complete that work. Many people make the mistake of using 40 hours per week for each craftsperson; this dramatically understates the backlog because there are usually significant hours each week that are paid for but not available to do work. Time spent on such activities as meetings, training, vacations, and daily routines should be removed from the crew capacity because this time is not available to work on backlog jobs.
Monitoring backlog on a trend chart helps the Maintenance staff understand the demand placed on the organization and enables resourcing decisions (such as whether to work overtime, hire a contractor for some tasks or move resources between crews) to be made based on objective data instead of gut feel. It also facilitates the scheduling process by ensuring that there is sufficient work to create a schedule for the upcoming week. Experience has shown that maintaining a backlog target of four weeks (plus or minus two weeks) provides a good balance between timely response to incoming requests and the ability to build a schedule that fully loads the crew with work.