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  • Janice Breen thinks this is interesting:

Variance is now the core of a project management system called earned value management, which tracks the project by considering effort "earned" against a budget only after it has actually been performed. For software projects, the variance is a measurement in person-hours (or person-days, person-years, etc.) that shows the difference between the effort planned to date on the baseline and the effort completed on the actual schedule.

From

Cover of Applied Software Project Management

Note

Variance defined. EVM (earned Value Managment) introduced.