“Velocity” highly used metrics in the Scrum world. After putting this statement down, now I am wondering to what extent is this statement correct. When I say “used”, I expect somebody to derive some benefit. Who is that somebody?
Ironically, there is no mention of word velocity in Scrum guide. Then how did it sneak into Scrum world? I am not sure, I guess, the basic human instinct of comparison paved it’s way into the Scrum world. Comparison to money involved in building the software, however no clue about how much money would be made.
I sometimes ponder why was “Velocity” the chosen word for amount of software a development team could deliver in a given timebox, why not speed. After all velocity is a physics way of quantifying speed, so what’s difference.
Let’s get back to school and recall the definition of Velocity and Speed,
- Speed is a scalar quantity that refers to “how fast an object is moving.”
- Velocity is a vector quantity that refers to “the rate at which an object changes its position.”
Definition of Scalars and Vectors
- Scalars are quantities that are fully described by a magnitude (or numerical value) alone.
- Vectors are quantities that are fully described by both a magnitude and a direction.
So now after refreshing our definitions of Speed and Velocity, how many times have you heard of direction while using velocity in Scrum. isn’t it just another numerical value of feel good or bad.
Choice of using “Velocity” was right, however its usage is turning out to be wrong, hence highly abused Agile metrics. The reason why the direction disappeared from velocity is due to the challenge in quantifying it. Also, velocity is incomplete without speed. Hence its imperative to determine the how close the increment displaced the product closer to the vision.