Features

An atomic story or feature is the simplest expression of: "What does a user want?"

Features need to be of similar size and can't be decomposed.

To build them, we practice depth-first design using the technique of the walking skeleton. 

A simple UI with complicated algorithm can be followed by the opposite. An apparently simple design change has a wide-reaching effects that require re-verification and a lot of thinking about edge case.

The principle, Schedule is Orthogonal to Workflow, suggests that there are two fundamental approaches to partitioning work:

1. By schedule
2. By workflow

• Traditional project management: schedules large work orders and aligns resources by workflow.
• Agile/craft methods schedule small work orders and aligns resources by schedule.