Laws in Software Development: 80/20 Rule in E2E Test Automation

“Achieving More with Less”

This article is one of the “Laws in Software Development” series:

• 80/20 Rule

• Broken Window Theory

• Parkinson’s Law: “work expands so as to fill the time available for its completion”

• Sturgeon’s law: “ninety percent of everything is crap”

• Murphy’s law: “Anything that can go wrong will go wrong”

• The 10,000-Hour Rule: “The key to achieving true expertise is simply a matter of practicing”

• Brooks’ Law: “Adding manpower to a late project makes it later.”

• Hosftadter’s Law: “It always takes longer than you expect, even when you take into account Hofstadter’s Law.”

• Conway’s Law: “Any piece of software reflects the organizational structure that produced it.”

• …

Table of Contents:
· The 80/20 Principle
· 20% Automated E2E (UI) Tests Cover about 80% of Code Base
· Regression Testing: 80% Automated E2E (UI) and 20% Manual (Exploratory)
· 80% of E2E Test Automation Effort on Test Stabilization and Maintenance

The 80/20 Principle

Many people know “The 80/20 Principle: The Secret to Achieving More with Less” from Richard Koch's best-selling book of the same name.

The 80/20 principle is all around us:

• 80% of sales come from 20% of clients.

• One-fifth of your time (equivalent to one day a week) produces 80% of your important work.

• 80% of crimes are committed by 20% of criminals.

• 80% of a company’s output is produced by 20% of its workers.

This page lists another 100 examples of the 80/20 principle.

Of course, 80% or 20% is just an indicative figure, so don’t get fixated on that exact number.

In this article, I will list three examples (that I observed) of the 80/20 principle in software testing and development.

20% Automated E2E (UI) Tests Cover about 80% of Code Base

In planning E2E Test Automation, there are commonly two extreme views: