A model of a Rock (Image from The Rock Crusher)
As obvious as it sounds, the Rock Crusher crushes rocks. A rock is the Rock Crusher’s metaphor or synonym for a backlog item. A rock can be any work a team may have to do, from a large initiative to a user story to a defect fix. A rock represents something we want.
A rock is well-formed if it has three attributes:
- An intent – It is objectively clear what outcome we want from the rock.
- A verifiable model – The intent results in a work product that can be objectively verified as done and that delivers the desired outcome for the rock.
- A test – There is an objective, demonstrable way of evaluating whether the verifiable model satisfied the rock’s intent.