A usage unit and a job describe different things about the work.
Frame a fictional document-triage comparison around the required result, retained responsibilities and uncertain assumptions.
Original planning material. No vendor price, staffing recommendation or financial forecast is supplied.
Define a comparable output
Suppose a fictional team wants to sort incoming project notes into a review queue. One proposal counts the usage needed to draft labels. Another describes the time a coordinator spends organising the entire queue. Those proposals do not yet cover the same work. Before comparing totals, specify whether the output is a suggested label, a checked classification or an accepted queue ready for another team to use.
Include exceptions in that definition. Some notes may mention several projects; others may omit the information needed to classify them. A proposal that assumes every note is straightforward cannot be compared fairly with a process that handles ambiguity. Keep unresolved cases visible and identify the next step that would make each case usable.
Keep responsibility in the description
A usage unit describes a form of consumption. A role can include judgement, coordination and responsibility for an outcome. Neither description can substitute for the other without explaining which task is moving and which obligations remain. In the triage example, someone still needs to decide how conflicting labels are resolved and who can change the queue.
Write the proposed allocation of work in ordinary language. The draft may suggest a project label and cite the sentence that supports it. A reviewer may confirm the label or leave the note unresolved. A coordinator may change the classification rules after reviewing repeated exceptions. These are illustrative responsibilities, not claims about a product or recommendations about staffing levels.
Make the next decision smaller than the whole proposal
If an important assumption is unknown, identify a bounded exercise that can clarify it. A small collection of fictional notes can reveal whether the proposed labels are clear enough to review. It cannot establish the cost of running an organisation or replace evidence about actual work. State what the exercise can answer and what remains outside its scope.
Preserve the quantities and assumptions separately so the comparison can be revisited. Avoid compressing uncertainty into a single persuasive total. The immediate decision may be whether to refine the task definition, gather better source information or stop exploring a particular approach. This guide does not supply a purchasing recommendation, promise a saving or treat people and usage units as interchangeable.