80-20 rule states that, for many events, roughly 80% of the effects come from 20% of the causes.
In Software Development
- 80% of users only require 20% of the features
- 80% features are done in 20% of project time (requirement added to the project very late)
- 80% of requirement conceptualized by everyone within 20% time of first meeting
I really like the iterative development which help to overcome from these facts because it break big cycle of project development to small feature development cycle, where we can prioritise the feature based on 80% users and start development. It is only successful when features are done within the iteration, and I really mean done (*agile methodology has done-done concept and that is very useful)
And just want to remind another agile practice known as Jamboree meetings for project planning to overcome from last point.
Actually I am quite fond of agile practices =)
In software Quality
- 20% top most reported bugs fixes, will eliminate 80% of the application error and crashes
- 80% of software quality is maintained by 20% of programmers
- 80% of bugs in an application are written by 20% of developers
- 80% of bugs are fixed in 20% of time
- 20% of a business application accounts for 80% of bugs
These facts are really interesting and helpful. Especially it helps, when you are making decision or doing planning.