CTQ means Critical to quality, which is defined to be a measurable characteristics or feature of a product or process whose standard of performance must be maintained in order to satisfy the customer. CTQ concept is most widely used in Six sigma.
CTQ plays a key role in identifying the metrics which is required by customer and to make them happy for conformance of their expectation by understanding which characteristic of a product are critical in its overall quality.
CTQ can be accessed by collecting voice of the customer (VOC). VOC helps to express the needs of a customer. These needs are converted into measurable terms by identifying the feature of a product or process.
How to make a CTQ Tree?
- Identification of voice of the customer
- Understand the customer requirement criteria’s or parameters
- Prioritize the criteria’s or parameters
- Convert the customer requirements into CTQ s (Critical to quality) that are measurable
Identification of voice of the customer
The initial step in deriving CTQ is getting VOC (Voice of customer) and VOB (Voice of Business) as they are the base for of CTQs. They can be collected by surveys, direct interview, feedback form, complaint forms, social media forums, etc. It should be collected from all segments of customers.
Understand the customer requirement criteria’s or parameters
Though we collect different VOC from customers, there should be an expert team identify the parameters or criteria which is being preferred by the customer.
For example, in an x online shopping company, the IT helpdesk team collected VOC from their customers and one of the VOC is “It takes too long to receive the product from your company”. Then the customer requirement parameter is: Quick Delivery of product
Prioritize the criteria or parameters:
Prioritization of criteria or parameters is an important step even though it is not reflected anywhere in CTQ tree. It helps to identify the whether the requirement of the customer is must to have or pleased to have features. Tools like KANO model will be helpful
Convert the Customer Requirements into CTQs
From the above example the voice of the customer is “It takes too long to receive the product”, which by adding measuring term as delay and the respective CTQ is delivery time. If there is a delay in delivery time, it leads to critical to overall quality.
A Typical CTQ tree should identify all the VOC and convert all into measurable CTQ s.