The 2080 software concept was developed from 2005 by elaborating on the existing Pareto principle, or "80/20" rule which states, in short, that in IT projects 80 per cent of the work is done before 20 per cent of completion time, and the remaining 20 per cent will take up 80 per cent of the time. While known to developers, this rule often creates a lot of frustration with managers. The 2080 Development concept further elaborates this principle to include functionality, build or buy decisions, and prototypes using agile methods.