The 80/20 principle in software

According to Vilfredo Pareto, 80 percent (or more) of outputs come from 20 percent (or less) of inputs. This is known as the 80/20 principle - sometimes called the 80/20 rule. The universe is - as Richard Koch puts it - "wonky". I am a huge fan of Richard's work and can highly recommend his books. Richard describes two ways of using the 80/20 principle:

• 80/20 analysis - requires investigation and is quantitative - it provides facts.
• 80/20 thinking - requires thought and is qualitative - it provides insight.

80/20 thinking can be applied to almost every aspect of business and life. To use it you first come up with a hypothesis based on your observations and/or intuition and then you test it by taking some action. Here is how you might use it as a software engineer:

• 80 percent or more of users use 20 percent or less of the features - if true, double down on these features, and possibly cut out the rest as they are a distraction.
• 80 percent or more of errors your users experience come from 20 percent or less of bugs - try focussing hard on your top bugs (getting down to the root cause) to see if you can radically reduce your customer-facing errors.
• 80 percent or more of app revenue comes from 20 percent or less of the users - double down on identifying and finding other similar users.

The 80/20 principle is a powerful tool, but it still requires effort to get the most out of it. Have a good think about how you can apply it - and then take some action and give it a go yourself.