Effort vs. Time in Agile
With Story Points, imprecision is high, but within a few cycles, it is reduced to manageable levels. Story points should be linear. A card with a two should need about half the effort of a 4. Yet, linearity doesn’t have to be perfect. Story points measure effort, not time.
The information economy brings a management challenge: measuring output from individual workers. In factory jobs in an industrial economy, the work is precise and quantitative — you produce so many widgets in an hour. You can be compared on equal footing with other workers. In information jobs, complex problems often need a larger team of people with different roles. People’s positions have become more diffuse and vague. It’s no longer clear who contributes what.
Cycle time measures the actual team’s Velocity. It measures the time it takes from working on a feature until it has been shipped and provides customer value. A coupled system maintains long Cycle times because many modules have to be changed in unison. It is hard to measure Velocity based on arbitrary Story Points. Development teams should understand the speed at which they can deliver working software.
Velocity is a relative and team-dependent measure, not an absolute one. Velocity isn’t about measuring the team. It is about having a coarse-grained forecast. Velocity is the rate at which a team delivers value to the customer. A team that completes many tasks but delivers no value to the customer should have zero Velocity. Velocity is a measurement, not a goal.
