Critical to Quality (CTQ) tree is a Six Sigma diagram which helps companies provide superior quality products to customers. Creating a critical-to-quality (CTQ) tree helps in translating customer requirements into measurable characteristics needed in the final product.

CTQ trees are used to interpret extensive and broader customer requirements into particular, precise, litigable and calculable performance demands. In other words, the team needs to translate the data gathered from customers (i.e. VOC) to drivers, and subsequently into a specific prioritized list of features (i.e. consider CTQ) in the product that meets those needs. Here is a simple example of a restaurant to identify what is the critical quality to their customers.

Critical to Quality Tree Example

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Component of Critical to Quality Tree

We can use a swimlane hierarchy Diagram to represent a CTQ tree which consists of three lanes: VOC, Drivers, and CTQ), or Critical needs, Quality Drivers and Performance Requirement. Do change names for the Lanes whenever it is necessary. CTQ tree is build up with the following three main components:

Voice of Customer (VOC)

The Voice of the Customer collects a detailed set of customer wants and needs, organized into a hierarchical structure like drivers and CTQ, etc.  They are then prioritized in terms of relative importance and satisfaction with current alternatives.


Drivers are the parameters on which a customer judges the quality of the product.


These are the calculable performance specifications that have to be met by drivers to satisfy clients. It helps the quality teams to measure the quality of a product and service and make sure it meets the client’s demands.

Learn By Example and Start with Easy Templates

CTQ Tree Example – Product Warranty Services

CTQ tree example

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CTQ Tree Example – Good Customer Service

CTQ diagram example

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CTQ Tree with Measurement and Target

CTQ Tree with measurement and target

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