Craft worker to planner ratio: is your planning function resourced or just overwhelmed?

The job gets called, the crew shows up, and then the waiting starts. The parts are not kitted. The permit is not ready. Nobody confirmed the scaffold. An hour of productive time evaporates before a single spanner turns.

Good planning is what prevents that waste, but only if each planner has a workload they can realistically carry. Pile too many craftspeople onto one planner and the backlog of properly planned jobs withers, the crew starts flying blind, and those wasted hours become the norm.

What it actually measures

The craft worker to planner ratio is the total number of maintenance craft workers divided by the number of planners, written as a ratio such as 20:1. A planner is a trained professional who works out the labour, materials, tools and safety requirements for each job and assembles them into a package before work begins. A planner who splits time with other duties should be counted only as the fraction of their hours actually spent planning.

How to work it out

Craft worker to planner ratio = Total craft workers / Total planners

A department of 80 craft workers with 2 planners:

Ratio = 80 / 2 = 40:1

That is double the best-in-class target. Each planner is trying to support forty people, which makes a healthy backlog of fully planned work all but impossible. Adding a third planner would bring it to around 27:1, still high but a real improvement.

Why planning is the highest-leverage job

Planning is not just one maintenance activity among many; it is the one with the most leverage, and the numbers behind that claim are worth knowing. The single biggest drain on a craftsperson's day is not slow work, it is waiting: waiting for parts, for permits, for instructions, for the equipment to come free. A good planner removes those waits in advance, and the effect on hands-on "wrench" time is dramatic. Detailed studies of real crews have found that a technician in a reactive, unplanned shop spends only around a third of the paid day actually working on equipment, while good planning can lift that toward a half or better. Put that leverage to work and the arithmetic becomes startling: take a crew of thirty at roughly a third wrench time, convert one of them into a planner, and the lift in everyone else's productive time can leave the remaining crew producing what something like forty-odd fully-utilised people would. One respected account framed it as gaining the better part of seventeen extra workers for the cost of a single planner. It is why the old rule holds that almost any team of more than a handful of craftspeople should consider making one of them a planner.

What good looks like

The widely cited target is twenty to one, one planner for every twenty craft workers, but it comes with conditions that matter as much as the number. It assumes planners who are fully dedicated to planning, properly trained, and working where at least three-quarters of the work is proactive rather than urgent response. In practice the sensible range runs from about fifteen to one up to thirty to one, depending on the craft mix and complexity; troubleshooting-heavy electrical work justifies the lower end, simpler routine work the higher. Two warnings bracket the band. Push the ratio much above twenty-five to one and the planner stops planning and becomes an expediter, chasing parts and permits for jobs already in progress, which defeats the entire purpose. Drop much below fifteen to one and you may simply be over-resourced. And none of it works in a reactive shop: hold a firefighting operation to twenty to one and you will just overload the planners you have, because they will spend their days being pulled into emergencies instead of preparing work.

Where it can mislead you

• Count only the hours genuinely spent planning. A planner who also expedites parts or runs capital jobs is a partial planner, and should be counted as the fraction of their time actually spent planning.
• The twenty-to-one target is heavily conditional, not a free-standing rule. It assumes a trained, dedicated planner and a mostly proactive environment; without those, the number means little.
• Watch for the expediter trap. A planner stretched past roughly twenty-five people stops preparing future work and starts chasing today's, the worst of both worlds.
• Track individual planners as well as the department figure; one overloaded planner drags quality down even when the average looks fine.

The craft worker to planner ratio tells you whether your planning function is actually resourced to prepare the work, or quietly drowning in it. Given how much every other number, wrench time, schedule compliance, reactive work, backlog, depends on good planning, it is one of the most consequential, and most under-appreciated, staffing decisions a maintenance organisation makes.