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The attrition & shrinkage drag

Free visual lesson · about 5 minutes · short quiz at the end

ccPlanning academy · capacity planning

The attrition & shrinkage drag

Why “required heads” and “recruited heads” are never the same number.

The big idea

You’re filling a leaky bucket.

Required FTE tells you how many you need in seats and productive. But people leave, and new ones aren’t productive yet. To hold a stable head of water in a leaky bucket, you have to keep pouring — capacity planning is mostly about sizing that pour.

hires in in seats attrition out

Drag 1

Attrition — the leak.

If you lose, say, 30% of agents a year, you must hire that many just to stand still, before any growth. Under-plan attrition and your headcount quietly erodes month after month while the forecast keeps rising — the classic capacity death-spiral.

Attrition has a shape

It’s not flat, and it’s not random.

New starters leave faster than tenured staff (early-life attrition), some months are worse than others, and a pay review or a competitor opening can spike it. Forecast attrition with the same care as volume — a single annual percentage hides all of this.

Drag 2

Shrinkage — the part-time tax.

As covered in forecasting, shrinkage means each head delivers far less than their contract. In capacity terms it’s a permanent multiplier on how many bodies you need. A few points of shrinkage drift adds real FTE to the plan — and the cost that goes with them.

Drag 3

The ramp — new heads aren’t full heads.

A recruit in week one isn’t a productive FTE — they’re in training, then ramping for weeks or months. Counting a bum on a seat as full capacity overstates what you actually have. We go deep on the ramp in the next lesson; here, just know it’s a third drag on effective capacity.

Putting it together

Plan for the gross, not the net.

Required (net, productive) heads, grossed up for shrinkage, plus enough hiring to cover attrition and the ramp lag — that’s the real recruitment number. It’s always bigger than the headline requirement, and forgetting any one drag is how plans come up short.

Size the pour

100 needed isn’t 100 hired

You need 100 productive heads held steady. At 30% annual attrition you lose ~30 a year just standing still — and because new starters ramp for weeks, each hire isn’t productive on day one.

Cover the leak and the ramp lag and the real recruitment number is well above 30 gross hires a year — plan the pour, not the puddle.

The takeaway

Required heads is the start, not the answer.

Attrition leaks the bucket, shrinkage taxes every head, and the ramp delays new ones. Forecast all three — with shape, not flat averages — and your hiring plan reflects the people you’ll actually have, not the people on paper.

Now test yourself ↓

1 / 8

Slides done? Here’s the same idea in a bit more depth — the part worth keeping.

In depth: why required heads and recruited heads never match

The required-FTE number tells you how many people you need in seats and productive. It never tells you how many to recruit, because you’re not filling a static tank — you’re holding a level of water in a leaky bucket. People leave, new starters aren’t productive yet, and every head delivers less than their contract. Three separate drags pull effective capacity below the headline number, and a plan that forgets any one of them comes up short.

The three drags

Attrition is the leak: if you lose 30% of agents a year, you must hire that many just to stand still before any growth at all — and attrition isn’t flat or random. New starters leave faster than tenured staff, some months are worse than others, and a pay review or a competitor opening nearby can spike it, so it deserves the same forecasting care as volume. Shrinkage is the permanent tax: each head delivers far less than their contracted hours, so it’s a standing multiplier on how many bodies you need, and a few points of drift adds real FTE and real cost. The ramp is the delay: a recruit in week one is in training, then ramping for weeks or months, so counting a bum on a seat as full capacity overstates what you actually have.

Plan the gross, not the net

The real recruitment number is required productive heads, grossed up for shrinkage, plus enough hiring to cover both attrition and the ramp lag. It’s always bigger than the headline requirement — sometimes dramatically so — and the danger is the capacity death-spiral: under-plan attrition and your headcount erodes month after month while the forecast keeps climbing, until you’re permanently chasing a gap you can’t recruit your way out of fast enough.

The principle to remember: required heads is the start, not the answer. Attrition leaks the bucket, shrinkage taxes every head, and the ramp delays new ones — forecast all three with shape, not flat averages, and the hiring plan reflects the people you’ll actually have.

Quick quiz

Five questions. Pick an answer to each, then check your score.

1. Why is capacity planning like filling a leaky bucket?

To hold a steady head of water in a leaky bucket you keep pouring — that’s the hiring plan.

2. What happens if you under-plan attrition?

At 30% attrition you must hire that much just to stand still, before any growth.

3. How should attrition be modelled?

New starters leave faster than tenured staff; a single annual % hides all of it.

4. In capacity terms, what is shrinkage?

A few points of shrinkage drift adds real FTE — and cost — to the plan.

5. What’s the real recruitment number?

It’s always bigger than the headline requirement — forgetting a drag leaves you short.