Quantifiable Backup Data (QBD)
EVM Terms
Reviewed by forProject Technology - updated Sep 2026
Quick definition: Quantifiable Backup Data (QBD) is documented, traceable support for a manager's percent complete assessment.
When progress is reported as a percent complete, the responsible manager has to judge how far along the work is. QBD is the documented backup for that judgment. It ties the reported percent complete to something tangible and measurable, such as a work product or a defined method, so the number isn't simply pulled out of thin air. Its purpose is to reduce the subjectivity in percent complete assessments and let anyone reviewing the number trace how it was reached.
What this means for you
A percent complete figure with no backup is just an opinion, and Earned Value built on it is only as reliable as that opinion. QBD gives the figure a basis that others can check, which makes the reported progress, and the Earned Value that comes from it, more credible.
Also known as
N/A
Used in
Physical Percent Complete assessment; Percent Complete (EV Method); EVMS compliance review evidence
See also
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.
© 2026 forProject Technology, Inc.
© 2026 forProject Technology, Inc.
