What is the key difference between CTQ and CTP?
There is a difference between somebody who wants you and somebody who would do anything to keep you: Unknown
What is the difference between stress when you are emotionally attached to someone and when you respect someone but not attached to them? In the first case, even if that person smiles a little less, you start feeling anxious but in the second case, even if the person is critically ill, you remain stable and try to help that person. In both cases, you remains the same but the stress level is different, depending upon the attachment with the person.
For any organization, there are many parameters to monitor and measure but there are few which can create a substantial difference in the overall performance. As for product and process performance, CTQ (Critical to Quality) and CTP (Critical to Process) are key product and process characteristics that require the specific attention of the process owner so that product quality to the customer can be ensured.
Let us understand the key difference and interrelation between the two.
CTQ (Critical to Quality): It is a tool used to identify the needs of the customer and translate that information into measurable product and process requirements.
CTP (Critical to Process): These are specifications for the process to operate correctly like machine settings, temperature settings, how often re-calibration should occur, how often to check machines etc.
When you’re developing new products and services, quality is important – not only to satisfy your clients but also to help you stand out from your competitors.
The key purpose of identifying CTQ and CTP:
- Identify what is most important for the customer (CTQ)
- Define the controls to monitor it (product characteristics)
- Identify the processes which can impact it (CTP)
- Define the control to monitor that too (process characteristics)
- Regularly monitor its effectiveness (CTQ and CTP)
The 3 key steps to identify CTQ/CTP:
- Determine the Need – What customer need are you fulfilling with your product or service? ask customers directly, or consult with customer service representatives or salespeople who frequently interact with customers
- Determine Drivers –What elements or characteristics will your customers mostly likely consider when judging the quality of your product or service? These are the elements that drive quality for customers who have the need you want to satisfy. Keep in mind that these are elements that must be present to satisfy customers.
- Create the Requirements –What process or product requirements are needed to make those drivers meet customer standards? These are the standards that must be met to meet customers’ expectations for each driver.
Following are some of the key difference between CTQ and CTH:
|S.No.||CTQ (Critical To Quality)||CTP (Critical To Process)|
|1||CTQ’s are identified to meet the requirements of the 4 key process owners (Organization, Customer, Enduser, Legal requirements)||CTP/s are identified so that manufacturing processes can help the organization to meet those CTQ for all 4 types of process owners|
|2||CTQ specifies the 6 key characteristics related to the product (Fitment, Function, Visual, Dimension, Performance, Testing)||CTP are generally process characteristics like Temperature, Pressure, Voltage, Time, Current|
|3||It allows organizations to understand the characteristics of a product or service that mostly drives quality for customers||It allows organizations to understand the characteristics of the process to meet the quality characteristics of the product with the support of internal customers|
|4||CTQ are generally Voice of the Customer (VOC) specified by the customer. Sometimes the organization also identified additional CTQ.||CTP is generally identified to meet CTQ.|
|5||CTQ are generally Critical to Customer (CTC) and are identified through customer drawing, technical specification and DFMEA||CTP are generally identified through PFMEA, technical specification sheet|
|6||The symbols for CTQ are generally specified by the customer in their Supplier Manual like Ford (CC, SC, HI, OS), GM etc.||Many times organization define their symbols for CTP, if not defined by the customer|
|7||Some of the common terminology for CTQ includes Maru A, Significant Characteristics, Critical characteristics etc.|
|8||DFMEA Study focusses on CTQ||PFMEA Study focusses on CTP|
- How often the organization define special/additional controls like an increase in sample size/foolproofing/SPC study for the CTQ and CTP?
- How often organizations link CTP in the manufacturing process to meet CTQ?
- How often the operators who have to understand and implement the CTQ and CTP on the shop floor are aware of it?
IATF 16949: 2016
This is the 105th article of this Quality Management series. Every weekend, you will find useful information that will make your Management System journey Productive. Please share it with your colleagues too.
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