Key takeaways
  • Backlog is measured in crew-weeks: outstanding approved work hours divided by weekly available hours.
  • Four to six crew-weeks is a common healthy range. Zero means no schedulable work and usually means reactive firefighting.
  • Ready backlog and total backlog are different. Work waiting on parts is not schedulable and should be tracked separately.
Why zero backlog is bad
Nothing to schedule means nothing was planned

A backlog of zero does not mean everything is done. It usually means work is being executed as it arrives, which is reactive maintenance with a tidy work order system.

Measuring it properly

Take the estimated hours of all approved outstanding work orders and divide by the hours the crew has available in a week. The result is expressed in crew-weeks, which is comparable across teams of different sizes and is far more useful than a count of open work orders.

Ready versus total

  • Total backlog. Everything approved and outstanding.
  • Ready backlog. Work that has parts, permits, drawings and access available, and could be scheduled this week.
  • Waiting backlog. Held for parts, shutdown windows, engineering or budget.
  • Only ready backlog can be scheduled, so a healthy total with an empty ready pool still means an idle crew.

Interpreting the number

  • Under two crew-weeks: likely reactive, or work is not being raised.
  • Four to six crew-weeks: enough to plan and schedule properly with a healthy queue.
  • Over eight to ten crew-weeks: the work is arriving faster than it can be completed, which means either a resource gap or an asset reliability problem generating the demand.
  • Rising steadily over months: the trend matters more than the absolute value.

Cleaning the backlog

A large backlog is often partly fictional: duplicate requests, work already done informally, jobs for assets that no longer exist, and requests that were never really needed. Reviewing anything older than six months and closing what is not genuinely required makes the remaining number mean something, and it is worth doing before drawing conclusions from a trend.

What backlog will not tell you

It says nothing about whether the right work is queued. A backlog of six crew-weeks composed entirely of low-value cosmetic jobs, while a critical PM is overdue, looks healthy and is not. Pairing backlog with PM compliance and with overdue work on critical assets gives the fuller picture.