Critical to Quality (CTQ) includes within its scope, the physical dimensions of height, width, depth and weight. Even the electrical characteristics of a product such as impedance, are also included within the scope of CTQ. Critical to quality study gives a vivid description regarding the requirements of quality in general terms but have deficiency in the specificity to be measurable. Nonetheless, they can be computed through the addition of customer-defined specifications.
A critical to quality (CTQ) is the flowchart process of finding out quality features or characteristics of the customer with the perspective to identify the problems. Put simply, critical to quality determines the inputs and outputs of processes and find out the path that influences the standard or quality of process outputs. CTQs are the main unit to measure features of a product or process whose presentation values or specification limits must be qualified in order to meet the customers’ requirements. They bring into design efforts or line improvement with the requirements of the customers.
CTQs correspond to the service characteristics or product features that are comprehensively defined by both the internal as well as the external customers. They may include the lower and upper specification limits or factors that are related to the service or product. According to the opinion of valued customers, a perfect CTQ analysis is an actionable and qualitative business specification methodology.
Especially, the unit that is produced under restriction is of great value. Even if it is lost, additional constraint’s time must be used to replace or rework on it. As constraints time determines throughput net profit of the entire system, the loss goes beyond what is found on the data and rework reports. CTQ projects done under restricted time period attain priority at the highest level.
Process of Implementation of CTQ:
- CTQ is used to determine the quality features or characteristics, in relation to the customer.
- It must be included while drawing a detailed flowchart of a business process.
- The flowchart developed by CTQ identifies problems as well as finds out their root causes.
- It is also used to bring development in a process.
Any project which is associated with CTx and consequently with critical customer requirements, have a great impact on the customer and on the business directly. A tree diagram is the most useful tool for ensuring the configuration or transformation from critical customer requirement to CTx.
A CTQ tree is usually applied to find out solution to the requirements of broad customer and carry the objective to get into quantified requirements in the easiest possible way. CTQ Trees is considered and used extensively in the methodology of six sigma.
Process for the Construction of CTQ Tree:
A CTQ tree usually decomposes a common and tough to measure customers’ requirements on the left side by following several steps and introducing more specific and variables that are easy to measure on the right side. It can be a straightforward as well as the most essential tool to measure the requirements of the customers when requirements of customers are broad, unspecified or not easy to measure. Sometimes this resulting decomposition can be executed through numbers of mathematically combinable (profit disintegrated into cost and price), but there are times when the variables are impossible to combined mathematically directly. A CTQ tree is the fastest tool usually used in a project prior its beginning, with an intention to measure the requirements of critical-to-quality, and not completely finding out the causes that directly or indirectly influences those measures.
Steps Determining Critical to Quality:
- Critical to quality is implemented at the time when the quality of a product is affected.
- It is applicable where an input determines what happens next in the process.
- Critical to quality is used to measure whether inputs or outputs are meeting needs.
There is a need to create a critical to quality tree in order to describe customer requirements in a specific measurable manner.
The following are the advantages of using CTQ tree:
- It helps in transforming unspecific customer requirements into specific requirements.
- It aids sigma teams in detailing broader specification.
- It gives assurance that all the aspects of the customer requirements are fulfilled.
Procedure for Drawing a CTQ Tree:
- First, it is needed to draw a detailed flowchart of the process.
Secondly, a thorough study of the flowchart is to be done and then a few questions are to be answered, such as-
- Who gets the output?
- What is the output?
- When is it required?
- How critical is it to the customer?
- Finally, the critical-to-quality steps are to be determined to identify problems in the process.
Steps to Create and Implement a Critical to Quality Tree:
- Determine the basic requirement of the customer.
- Identify the customer's first tier of requirements.
- Identify the customer's second tier of requirements.
- Stop when quantifiable requirements are reached.
- Confirm your final requirements with your customers.