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Quantifiable Backup Data

Quantifiable Backup Data (QBD)

EVM Terms Reviewed by forProject Technology - updated Sep 2026
Quick definition: Quantifiable Backup Data (QBD) is the objective, verifiable evidence used to support an assessment of work accomplished — the documented basis behind a percent complete claim.

QBD turns a judgment into something someone else can check. Rather than asserting that a Work Package is 60% complete, the Control Account Manager points to a defined basis: a checklist of steps completed, progression through a documented methodology, status drawn from an external system such as MRP or an Agile tool, or items finished against items planned. The basis is defined during planning, before work starts, so how progress will be claimed is agreed up front rather than constructed after the fact. QBD is what keeps assessment-based earning methods from being purely subjective.

Why it matters

Assessment-based earning methods are only as trustworthy as the evidence behind them. Without QBD, a percent complete figure is an opinion, and EVMS surveillance will treat it as one. With it, the same figure becomes a claim that can be independently verified.

Also known as
N/A
Used in
Physical Percent Complete assessment; Percent Complete (EV Method); EVMS compliance review evidence

FAQ

Who defines the Quantifiable Backup Data for a Work Package?
The Control Account Manager, during planning — before the work starts. Defining it after progress has been claimed defeats the purpose.
What counts as Quantifiable Backup Data?
Whatever gives the assessment a documented, checkable basis — a checklist of completed steps, progression through a defined methodology, status from an external system such as MRP or an Agile tool, or items finished against items planned. If the basis is purely a count of like units, Units Complete may be the more appropriate Earned Value Method.
Definition maintained by forProject Technology.
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