Critical to Quality (CTQ) (2024)

Picture a world where customers LOVE your products and rave about your service.

In the relentless pursuit of delivering products that meet and exceed customer expectations, it is necessary to understand Critical to Quality (CTQ) measurements.

Think about every product you’ve ever loved. Think about companies you willingly follow on social media and tell all your friends and relatives about. Think about those brands where their customers get tattoos of their logos!

These are not aspirations. They are tangible manifestations of CTQ requirements. CTQ requirements are the linchpin. They ensure your output aligns seamlessly with what customers demand. You must understand Critical to Quality measures if you want a fanatical customer base.

Critical to Quality requirements relate to customer expectations and needs around the quality of your output.

Some examples of CTQ requirements are:

• Mobile phone screens do not break when dropped from three feet onto concrete.
• Engine part size variance of less than 0.5%.
• The tensile strength of a steel girder must be at least 1000 MPa.

Critical To Quality Requirements vs. Drivers

Drivers, or Critical to Client requirements, are what your clients want, expect, or need.

Critical to Quality requirements are the conditions your output must meet to answer the drivers. You’ll often have more than one CTQ requirement per driver.

Occasionally–especially in the construction industry–you might find that the drivers are specific enough to translate directly into CTQ requirements. Generally, though, the two will be different, but the CTQ will flow from the drivers.

Examples of drivers and CTQ requirements

How to Develop Critical to Quality Requirements

A CTQ tree is a common tool used to put together CTQs.

It consists of three primary sections:

• Customer requirement: This is what the customer might express to you as a concern. For example, “I like my coffee really hot and milky!”
• Drivers: The customer requirement is broken down into action points. For example, “High temperature” and “High percentage of dairy milk.”
• CTQ requirements: These are your manufacturing guidelines to meet the drivers. For example, “Full-cream pasteurized dairy milk” and “Milk frother heats to at least 203°F”.

The end result for the above example would look something like this:

1. Customer requirements

Start with your customer’s requirements. What do your customers want in regard to quality? You’ll typically come up with more than one of these. Use each in a different CTQ tree.

2. Drivers

Break down your customer requirements from the previous step into drivers. Think about what exactly your customer is really expecting. Or, to put it another way, what traits of your end product must be in evidence for the customer to decide that it has met their requirement?

3. CTQ requirements

From the drivers, decide on what internal requirements you need. These will help you to produce a product that meets the driver’s conditions. They are also benchmarks that you would use to perform QA tests.

Elements of Good Critical-to-Quality Requirements

Good CTQ requirements are like SMART goals:

• Specific: They need to be clear and easily understood.
• Measurable: Unlike customer requirements, which can be highly subjective, CTQ requirements must be objective. If you can’t measure it, it’s not a good CTQ.
• Applicable: They must directly relate to your customer requirements. Remember, CTX requirements are customer-focused.
• Testable: Your staff must be able to check that your product meets CTQ requirements.

CTQ Videos

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