Each year, Ministry of Testing launch a #30DaysOfTesting challenge. This year the topic is ‘Quality‘. The challenge began in March, but I was a little late getting started. So, throughout April and May, I’m going to be publishing a series of blog posts where I share my progress.

Day 19 – Read and share your thoughts on Principle 5 of Modern Testing

We believe that the customer is the only one capable to judge and evaluate the quality of our product.

The fifth modern testing priciple

What an interesting idea!

Until now, I’ve been mostly preoccupied on the views of business stakeholders when it comes to quality. I feel this highlights why this principle is so important.

On Day 4, I may have looked at the perspectives of quality from the point of view of both the business and the customer. However, my main area of focus has generally been the business and the team (who work for the business).

I agree with this principle to an extent. The customers point of view is very important. But should they be the sole judge?

Why Should The Customer Be The Judge?

Lets have a think about this. Why are we developing the product?
To make money! That is usually how most business’ work.

Money is made by providing the customer with something they need.

So, if a product is being developed for the customer, and the customer has the best understanding of their own needs, it seems pretty obvious that they should be the ones deciding if its fit for purpose.

Why Should The Business Be The Judge?

The customer may understand their own needs the best, but the business will understand how the product works best. This gives the business the capability to actually assess the quality of the product and identify areas for improvements. It also means the business will know if what the customer wants is even feasible.

If the cost to develop the product exceeds what the business stands to gain, then there would be no reason for the business to develop the product or even maintain it long term. This would be a loss for both the business and the customer.

The customer will judge based on what they need. The business will judge based on what they stand to gain from developing the product.


The cost of developing the product must not exceed what the business stands to gain from developing the product in the first place. The customers vision must be feasible, but the customer may not have a full understanding of what is feasible.

During his MOTrix webinar about the future of technology, Leigh Rathbone makes a good point about the importance of customer driven innovation. The customer should drive quality as well. However, the business must have something to gain or it will all be for nothing and both the customer and business will lose out.

It is all about the balance between what the user wants or needs, and what the business can provide.

The customer should drive quality (and innovation), but the business needs to control it.

Further Reading


#30DaysOfTesting – Progress so far

  • Day 1 – Lookup some definitions of what ‘Quality’ is and share your own definition on The Club
  • Day 2 – Read and share a blog post on Quality
  • Day 3 – Pick a book to read that discusses ‘Quality’ and share on The Club why you’ve chosen it
    • Will be completed along with Day 30
  • Day 4 – Capture five different perspectives on Quality and share their similarities and differences.
  • Day 5 – Get some members of your team to join you in a game of Quality Jenga
    • Can’t complete due to COVID-19 Pandemic. Not sure how to play Jenga when everyone is working from home.
  • Day 6 – Find out what ‘Quality’ means to your teammates
  • Day 7 – Follow 5 people on social media who are sharing or working around ‘Quality’
  • Day 8 – Sit with your team and find out how you’re building ‘Quality’ into their work
  • Day 9 – Contribute to a discussion on The Club about ‘Quality’
  • Day 10 – Find and read feedback from your customers. What does this tell you about the quality of your product?
  • Day 11 – Watch the AMA on Quality Engineering and join the conversation on The Club
  • Day 12 – Create a visualization that can help describe the different aspects of ‘Quality’
  • Day 13 – Find, listen and share a podcast on ‘Quality’
  • Day 14 – Read about ‘Quality Characteristics’ and share a characteristic that matters to you
  • Day 15 – Ask five different teams within your organisation what is the most important quality characteristic for them
  • Day 16 – Pick a ‘Quality Characteristic’ and use it to guide an exploratory testing session
  • Day 17 – Pick an app that you use daily, what quality aspects of the app encourage you to use it?
  • Day 18 – Share a bug you have found in your system and the quality characteristic that is was potentially affecting
  • Day 19 – Read and share your thoughts on Principle 5 of Modern Testing
  • Day 20 – Look up and share a definition on Quality Engineering
  • Day 21 – Share a resource on how you might measure quality
  • Day 22 – Find out what metrics your internal stakeholders care about and why
  • Day 23 – Map out how ideas get to production and look for the biggest bottlenecks or problems
  • Day 24 – Share what quality metrics you track or what metrics you want to track
  • Day 25 – Research how an external company improves their ‘Quality’ – how can your team adopt these improvements?
  • Day 26 – Create a way to report to your stakeholders your team’s views on quality
  • Day 27 – What is the role of a quality coach?
  • Day 28 – Research the different between Functional Quality and Structural Quality
  • Day 29 – Contribute to a discussion on The Club about whether there is a difference between code quality and software quality
  • Day 30 – Share something you’ve learnt from the book you chose to read on Day 3.