This article expands on the “Resources and Capacity” thread in Management Retrospective.

“How many engineers per product” and “how many developers per tester” — ratios like these are often treated as a yardstick of efficiency in discussions. They are indeed easy to compute, easy to compare, and easy to make look well-grounded in reports. But at best they can only describe a state at a single point in time, and they rarely support decisions — the moment the business stage, complexity, risk, or existing assets change, an old ratio will mislead new decisions.

What follows is a general principle, not a scheduling formula for any particular team; specific ratios always have to be recalculated against your own goals and constraints.

Align at the Moment Resources Appear

Headcount planning is best done at the moment resources appear: a new budget, a headcount opportunity, a signal of business expansion — or, conversely, a market change and goal contraction — are all moments to realign. At such moments the first thing to ask is not the ratio, but three questions:

  • What goals will we need to take on going forward?
  • Where are the gaps in our current capabilities?
  • What can no longer be handled through ad-hoc coordination?

A ratio answers none of these. Whether ten people is too many or too few depends on what you need to deliver, how much maintenance responsibility you carry, and how complex your dependencies are. Talking about ratios apart from goals and constraints is like deciding on the answer first and then going looking for the question.

When Resources Change, There Are Only Three Paths

Add people, cut goals, or change the approach — each has its own conditions and costs.

Adding people fits when there is a clear expansion of resources and the future is genuinely expected to grow. Note that “we’re busy right now” alone cannot automatically imply “we should expand” — being busy may be a process problem, a dependency problem, or simply goals set too full. A fast-growing area asked for more people according to an old ratio; once broken down, the real bottleneck was slow external approvals and key processes that had not been standardized. Adding people directly would only make more people wait at the same entry point.

Cutting goals fits when all parties consistently acknowledge that external conditions have changed and the original expectations no longer hold. Cutting goals sounds like a step backward, but it is actually a kind of honesty: it returns commitments to the objective market instead of clinging to a number that has already become invalid. In many situations it is more responsible than “toughing it out.”

Changing the approach fits when the goal still matters but resources cannot be increased. By negotiating a change to the implementation, scope, or pace, you require all parties to acknowledge the cost rather than letting one team quietly absorb it. The hard part is not changing the approach itself — it is making everyone see who bears the cost of the change.

Fix the Bottleneck Before Adding People

Back to that “fast-growing, asking-for-more-people” area: the team initially applied for expansion according to the old ratio, but later first broke apart the dependencies, clarified interfaces and deadlines, and confirmed there was still a real capability gap between future goals and workload before deciding to expand. Conversely, when the market changed and partners jointly lowered expectations, cutting goals was more honest than clinging to the old ratio.

These two things are essentially the same: replace “is the headcount enough” with “where is the gap between goals and resources.” Whether the gap lies in capability, in process, in dependencies, or in raw headcount, the solutions are completely different — using the single tool of adding people to handle every gap only spends money and people in the wrong places.

Ratios Can’t Replace Judgment

Ratios will not disappear, and they should not — as a description they are still useful. What really needs to be avoided is letting them replace judgment.

There is only one standard for judgment: when resources change, can information be aligned in time, and can the choice be made jointly by the people who bear the consequences? Whoever can answer “what does this round of change mean for the goals, and should we add people, cut goals, or change the approach” is doing headcount planning; whoever can only report the ratio is merely reciting numbers.

So the next time someone comes to discuss headcount with a set of ratios, I will not first ask whether the ratio is right — I will ask: what are our goals now, where is the capability gap, and what assumptions is this ratio built on. If you can answer clearly, the ratio is worth discussing; if you cannot, the ratio is just a numbers game.