What is the Pareto principle?

• The Pareto Principle states that roughly 80% of all the outcomes come from 20% of the causes (inputs).
• The Pareto Principle is also known as the 80:20 rule.
• Italian economist Vilfredo Pareto developed this principle in 1896.
• Pareto observed that in his garden, only 20% of the plants were giving 80% of the fruits.
• Later, Dr. Joseph Juran made this principle popular and he used this in the production processes of businesses.
• Pareto later realized that this proportion could be applied to most of the aspects of our lives.
• We should remember that this is not a standard rule. Sometimes numbers might get changed i.e. they may become 90/10 , 60/40, etc.
• Most of the things in life are not evenly distributed and a few people will contribute more than the others. Understanding this fact is important for software testers.
• As software testers, we should always understand the advantages of “What if we spend less time in testing and get more things done?” by implementing the Pareto Principle.
• This 80:20 rule always gives priority to 20% of the factors that will give the best results.

How does the Pareto Principle help in decision making?

The Pareto Principle can be used to make the best decisions during problem solving processes. Below are the steps: 

1. First, we should always identify all the problems that our team is facing.
2. Next we should identify the causes of the problems.
3. After identifying the causes, we should group all problems into similar groups because if we find one solution, it can solve all the problems in that particular group.
4. Next, we should assign a value to each problem just to understand the extent to which businesses are getting impacted by these problems.  .
5. Next, we should develop a plan to solve the most important problems in such a way that solving only 20% of the problems should generate 80% of the desired results.

How the Pareto Principle is implemented in the software industry 

• In every company, all the customers will not be able to contribute more in company revenue and the company will be having a few customers (gold customers) who will be contributing more to the company-revenue.
• So as testers, we should identify the most valuable customers and their business processes and we should try to keep them happy by providing good service.
• Always 80% of a company’s business will come from 20% of the customers.
• We should always understand a customer’s business and apply it in our test cases , which will help us to run appropriate tests according to customer requirements.
• We should always try to get detailed information from the gold customers and try to solve their issues, which will help us to improve our test cases.
• In any product, 80% of the issues will be coming from 20% of the modules. We normally refer to this as Defect Clustering, which is one of the testing principles.
• As a tester, if we clear those defect clusters then the health of the product will increase.
• 80% of the results will be given by 20% of the testers, which can be used to evaluate the team performance.
• 80% of the testing jobs require 20% of the testing skills and this will help you in switching jobs and promoting career growth.
• 80% of the testing time will be spent on the 20% of the modules ( impacted areas). This will help to monitor whether the testing team is focussing on the right areas.

Advantages of Using the Pareto Principle

• This principle helps us to create the maximum impact with the least amount of work.

• The entire team will have a clear vision of all the priorities.
• The daily productivity will get enhanced.
• All the work can be segregated into different groups, which will help in managing the work more efficiently.
• The team will be able to develop and implement a more focused strategy. 

Disadvantages of Using the Pareto Principle

• There is a common misunderstanding that  we can achieve 80 % results with 20% effort , but this is not a standard rule. The numbers might change and also the 20% and 80% values will not indicate the actual efforts that we are putting in. It will show causes and consequences of the work.
• We have to put 100% effort into that 20% focus to achieve an 80% result.

Conclusion

The Pareto Principle guides us to spend more time on things, which will give better results. We should give more priority to the tasks that come under 20% of focus to get 80% results. Moreover, we should have a clear idea on how and when to use this principle in order to get good results. Applying this principle in QA activities helps us to decrease the testing time and increase the efficiency of the product. It is also a very powerful tool for reducing bugs in production by reducing the overall testing effort.