Crystal

The Crystal family of methodologies was developed by Alistair Cockburn in the mid-1990s. The methodologies are named after colors and/or gemstones to indicate the «weight» of methodology needed (as per the team attributes or strategic needs).

The most famous is also the lightest, called «Crystal Clear,» used for small teams with co-located members working on noncritical tasks. The family focuses on efficiency and habitability as constituents of project safety.