Maintenance & Reliability worked example

Maintenance Backlog with preventive backlog hours of 110 hr: a worked example

This worked example runs the maintenance backlog numbers for a tougher week than the baseline: preventive backlog hours of 110 hr instead of the typical 220 hr. Roll up PM, corrective, project, and deferred work into total maintenance backlog hours.

The inputs for this scenario

  • Preventive (PM) backlog hours: 110 hr (the input this scenario stresses; the baseline uses 220)
  • Corrective repair backlog hours: 160 hr (held at the documented default)
  • Improvement project backlog hours: 90 hr (held at the documented default)
  • Deferred work backlog hours: 60 hr (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Total maintenance backlog = PM backlog hours + corrective backlog hours + project backlog hours + deferred work hours.
  • Total Maintenance Backlog works out to 420 hr at these inputs, and this is the headline figure for the scenario.
  • PM Backlog works out to 110 hr at these inputs.
  • Corrective Backlog works out to 160 hr at these inputs.
  • Project and Deferred Work works out to 150 hr at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where preventive backlog hours sits at 220 hr and the headline result is 530 hr, this scenario comes in 20.75% below the baseline at 420 hr.
  • Use it at weekly planning and scheduling meetings, when sizing crew capacity, or when reporting backlog trend and weeks-of-work to management. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Total Maintenance Backlog: 420 hr (headline result)
  • PM Backlog: 110 hr
  • Corrective Backlog: 160 hr
  • Project and Deferred Work: 150 hr

Run it with your numbers

  • To rerun this with your own numbers, open the live Maintenance Backlog calculator, set preventive backlog hours to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.