Contractor cost: how much of the budget walks out the door to outside firms

The budget review arrives and the maintenance manager is asked why the cost line is so high. There are several possible answers, but nobody can say at a glance how much was internal labour, how much was materials, and how much went straight out the door to contractors.

Without that split, the number is hard to act on. Contractor cost gives you that one slice cleanly, so you can track it, compare it, and decide whether outside spend is working for you or quietly running away.

What it actually measures

Contractor cost is the percentage of total maintenance cost spent on outside contractors. It covers all payments to external firms for maintenance on site, their labour and materials, across routine work, outages, shutdowns and turnarounds, and it includes contractors brought in to replace end-of-life equipment, so that heavy replacement spend cannot hide behind a separate capital budget. It excludes contractors hired for plant expansions or new builds.

How to work it out

Contractor cost (%) = (Contractor cost ($) × 100) / Total maintenance cost ($)

A plant spending $2,840,000 on contractors against a total maintenance cost of $11,200,000:

Contractor cost = ($2,840,000 × 100) / $11,200,000 = 25.4%

Just over a quarter of the budget left the organisation. Whether that is the right number depends on the plant's mix of specialty work and its in-house capability, but at least the conversation is now grounded in a fact.

What good looks like

There is no universal benchmark, and that is not an oversight; the right level is genuinely a matter of strategy. The best-run operations use contractors for specific, deliberate purposes: specialty crafts they cannot justify employing full-time, peak or abnormal workloads such as outages and turnarounds, and specialist tools or technology like cranes or thermographic surveys. Track the figure monthly and annually against your own baseline; a rising line with no matching rise in specialty or shutdown activity is the signal to look closer.

The "imaginary savings" trap

There is a seductive argument that maintenance should simply be handed wholesale to a contractor who can do it more cheaply, and it deserves a hard look, because the savings are often more imaginary than real. When a contractor genuinely is cheaper, it is usually not because contract labour costs less per hour; it is because the contractor plans the work, schedules it, and strips out the waste, the very disciplines an in-house team could adopt for itself. Studies of heavily outsourced operations have tended to find that wholesale contracting did not lower cost at all, and that the most fully contracted arrangements scored worst across the board. None of which is an argument against contractors, who are indispensable for specialty work and peak loads; it is an argument against treating outsourcing as a substitute for fixing your own planning. Know what you are really buying: a capability you genuinely lack, or an excuse not to build one.

Where it can mislead you

• Do not read it alone. The labour side of contractor spend often needs examining separately through the contractor hours metric, since high day rates can make modest hours look like heavy cost.
• Include end-of-life replacement consistently in both the top and bottom of the fraction, or contractor use looks lower than it really is.
• A high percentage is not automatically a problem. Some plants deliberately lean on contractors for certain crafts; the real question is whether the level is intentional and cost-effective.
• Exclude capital expenditure for expansions and improvements from both figures, or the denominator swells and the metric understates how much you rely on contractors.

Contractor cost makes the outside-spend portion of your maintenance budget visible, comparable and improvable. It will not tell you whether that spend is wise on its own, but it turns one of the budget's biggest moving parts from a vague worry into a number you can actually manage.