What this market sizing model should accomplish
A useful market sizing model exists to estimate reachable commercial potential and expose the assumptions that drive it. It should make the decision, scope, assumptions, evidence standard, and required output explicit before the team starts collecting material.
For operating teams, the practical method is to combine top-down triangulation with a bottom-up customer, usage, price, and reach model. This keeps the work focused on a management choice instead of producing a generic document.
Inputs and evidence to prepare
Prepare customer counts, usage frequency, price, segment boundaries, adoption constraints, and source dates. Mark every important statement as verified evidence, an assumption, or an unresolved research question.
Use consistent definitions, periods, units, segments, and sources. That lets another reviewer reproduce the logic and update the work when new evidence arrives.
Quality controls before using the result
The central control is simple: present ranges and confidence levels instead of a single unsupported market number. Review calculations, citations, ownership, and decision thresholds before publishing or acting.
AI can accelerate structure, synthesis, and first-draft analysis. The accountable owner still decides whether the evidence is sufficient and whether specialist review is required.