Different Units on Each Side
The four ways the two sides of a capacity account end up in different units, and the conversion sheet that makes them comparable in an afternoon.
The same commitment, as each side recorded it
Five of the six lines are the same commitment recorded in two incompatible forms, and the sixth differs only in state. Neither side is careless; they are keeping different books for different purposes and nobody reconciles them. This is one employer's own comparison, not a benchmark.
The supply side counts in net hours because that is what the deductions are made of. The demand side counts in people, days, sprints and sometimes money, because those are the units commitments are made in.
The unit used in “Different Units on Each Side” must remain stable from capacity estimate to actual result. For organisations assessing a structured route to daily schedule template in relation to daily schedule template, time and project reports can support that reconciliation, provided leave, support work and corrections retain their own definitions.
Neither is wrong, and the plan is the subtraction between them, so one of them has to move. Which one, and where the conversion happens, is a decision almost nobody takes deliberately.
As a separate benchmark for “Different Units on Each Side”, see Agile Alliance learning resources. Keep source data, calculation, override and decision visible as distinct steps.
The four mismatches
Net against gross: supply has subtracted leave and support, demand has not. People against hours. Days against hours, where a day is assumed to be eight hours of work and is not. And money against capacity, where a budget is treated as though it were people.
Each is a factor, each is knowable, and each is usually in somebody's head.
Net against gross is the big one
A demand side working in gross hours and a supply side working in net will disagree by the shrinkage rate — twenty to forty per cent — on every single line, consistently, in the same direction.
That is not a rounding difference. It is the difference between a plan that fits and one that does not, and it is invisible because both sides are using the word hours.
A day is not eight hours
A person-day of planned work is the available fraction of a working day, which after meetings, support and the ordinary overhead is closer to five or six in most knowledge work.
Where demand estimates in days and supply plans in hours, this factor alone produces a twenty-five per cent overcommitment, and it is applied silently by everybody.
Money, which converts both ways badly
A budget that covers X hours at an average rate does not mean X hours are available, because rates differ by person and because the people the budget assumes may not exist.
Treating budget as capacity is the most common senior-level version of this error, and the correction is one sentence: funding permits capacity, it does not create it.
The conversion sheet
One page, four rows, agreed once:
| From | To | Factor | Agreed with |
|---|---|---|---|
| FTE quarter | available hours | 468 | Operations, March |
| person-day | available hours | 6 | Delivery leads, March |
| sprint (2 weeks, 1 person) | available hours | 60 | Delivery leads, March |
| budget | capacity | not convertible | Finance, March |
The last row is the important one, and stating it explicitly is what stops the conversion being attempted.
Where the conversion should happen
Once, at the boundary, by the planner, with the result sent back to the claimant for confirmation. Not repeatedly, not in both directions, and not by each reader individually.
A figure that has been converted twice by different people using different factors cannot be reconciled with anything, including itself.
Making the mismatch visible before fixing it
The fastest way to get agreement on a conversion sheet is to show the two sides' totals next to each other for one real period.
A difference of a person and a half in a team of six is not an abstract methodological issue, and it produces a conversion sheet in a single meeting where a process proposal would not.
Who owns the factors
The planner proposes, operations and delivery agree, and finance agrees the money row. Once a year, with a date.
Factors owned by nobody drift: somebody uses 7.5 because that is the contractual day, somebody else uses 8, and the plans stop being addable.
What to do when a claimant insists on their unit
Accept it. The book records the claim as given and the conversion beside it, with the factor named. Arguing a sponsor into hours wastes the meeting and gains nothing the conversion does not.
The only thing worth insisting on is that the converted figure goes back to them, so that the conversion is visible rather than private.
Why the factors feel arbitrary and are not
Six hours in a person-day sounds like a judgement and is a measurement: it is what the interrupt and meeting figures leave once they are subtracted.
Where somebody objects to a factor, the useful reply is to show the descent it came from rather than to defend the number. The factor is a conclusion, and the evidence for it is the supply side of the account.
The conversion that should not exist
Story points, velocity and similar internal measures convert to hours only within one team and only for a period. They are deliberately relative, and converting them into a capacity account imports their relativity into a document that has to be absolute.
Where a team plans in points, the conversion belongs at the team boundary and the factor belongs to that team alone, re-measured each quarter.
The sentence that ends most of these arguments
"We are using 468 available hours per FTE quarter and six hours per person-day; if you are using different factors, that is where our numbers differ."
It is checkable, it is specific, and it moves the discussion to one of four numbers instead of to whose plan is right.