Quality is easily the make or break element of any product, service, or project. Organizations push to deliver prime quality for two significant reasons, first to satisfy their clients and second to stand out from the competitors.

In layman terms, Critical to Quality requirements relate to customer's expectations and needs with the quality of the output delivered. While the need for the CTQ requirement is clear, it is not always easy to identify the exact features that provide the quality in the customer's eyes. This is where the Critical to Quality Tree comes into the picture.

Critical to Quality tree is a diagram tool that helps in translating broad customer needs into specific, actionable, and measurable performance quantifiers. For example, "Deliver quality pizza and good service” is too broad a term to do much about it. CTQ tree is used to break this requirement down to actionable items.

Developing Critical to Quality Tree

Step 1: Identify Critical Needs

Critical needs are the needs that your product or service needs to satisfy. The first step in the process of developing a CTQ tree is to identify critical needs. Conduct needs analysis or even ask the client or customer what they require. It would help if you also brainstormed along with other team members to identify needs that the client might not have recognized. It is best to define these needs in broad terms as this will prevent you from missing out on essential pointers.

Step 2:  Identify Quality Drivers

Quality drivers are the factors that must be present in your product or service for the customer to think that you are delivering a quality product or service. This level will require effective communication with the client or the customer. It is of utmost importance to spend a considerable amount of time on this to not miss out on any of the drivers.

Step 3: Identify Performance Requirements

Once you have identified the quality drivers, you need to decide on these quality drivers' minimum performance requirements. There are several factors that you will have to consider while deciding on the performance requirement. Examples of such factors are the availability of resources, availability of the technology, etc.

Example of CTQ tree

Now that you know how to create a CTQ tree let's revisit our initial need statement and see how we can break it down.

Need:

 Deliver quality pizza and good service

Drivers

1. Variety of pizza

2. Quick Service

3. Use of good ingredients

Performance Requirements

1. Variety of pizza

- Diversity in the pizza toppings

- Include the option to add seasonal toppings

2. Quick Service

- All customers addressed within 2 minutes of

- Orders fulfilled within 10 minutes

3. Use of Good Ingredients

- Including gluten-free pizza

- Calories of each item mentioned          

We hope the example will give you an idea about the creation of the Critical to Quality tree and its steps. While the tool is a part of Six Sigma, it can efficiently and effectively be used during a project or product development. You can explore similar essential concepts of Lean Six Sigma with CP's Lean Six Sigma Courses and apply them in your domain to deliver excellent quality products or services. Happy Learning!