Key Characteristics (Kc)

Key characteristics (Kc) act as key specifications of a product or process which is essentially required to meet desired quality level, customer expectations, safety, reliability, durability, and statutory and regulatory requirements.

Not all product features or process parameters are critical, but a few features/dimensions of the product are critical to quality or safety. However, a few product features are essential to ensure the quality, safety, and reliable function of the product.

Few process characteristics play a big role in achieving the desired quality product. Failure of maintaining process characteristics results in a defective end product or defect in the product.

Types of key characteristics

Key characteristics are further divided into three types.

Product Characteristics

Process Characteristics

Service Characteristics

The following table provides a high-level overview of product, service, and process characteristics. Not all characteristics serve or act as key characteristics, but a few characteristics play a big role to achieve the desired product function, service deliverable.

Product Characteristics	Process Characteristics	Service Characteristics
Meeting regulatory requirements	Critical formula	Precise service
Reliable and Safe Product	Process Method	Accurate service
Appealing and Good aesthetic	Chemical ratio	Quick Turn around time
Color and Finishing	Process material specification	On-time service,
Performance of product	Mixture Ratio	On-time delivery,
Fail Safe	Environmental Control	Quick service,
Factory of Safety		First-time pass service,
East to operate / drive		Customer satisfaction,
Durable		Trustworthy,

Significance of Key Characteristics in Quality Management System

A product or process key characteristics essential to monitor and control in manufacturing as well as in the service industry. 

Let’s review why Key characteristics must be measured, monitored, and controlled?

1. To achieve the desired quality level during the manufacturing process & during service or after-sales.
2. To avoid non-conformity in the product or service
3. To meet statutory and regulatory requirements
4. To meet the customer satisfaction level
5. To deliver a quality, durable and reliable product.
6. To deliver safe products and services.
7. To develop product and process.
8. To avoid product failures in the field.
9. To avoid product recall and customer dissatisfaction.
10. To mitigate the risk in product design, manufacturing, and service.
11. To control the cost of quality!

Key characteristics can further be linked to various elements in the QMS.

a. FMEA (D-FMEA or P-FMEA)

B. Control Plan

c. Statistical Process Control

d. Check-sheet

e. Process Audit

f. Product Audit

g. Mistake-proofing

h. Risk Management

i. Business Continuity Plan (BCP)

J. Total Quality Management

k. APQP

l. Supply chain risk management

How to control key characteristics?

Key Characteristics can be controlled in the following way,

Step 1: Identify and define KC in D-FMEA considering the safety, durability, reliability, quality expectations, performance, statutory and regulatory requirements of products. For service, identify and define key characteristics during service manual design.

Step 2: Cascade product & process key characteristics in part drawing and P-FMEA. Define service key characteristics in the service manual.

Step 3: Define control parameters of product and process key characteristics in the control plan. Define service key characteristics in the service checklist or control plan.

Step 4: Conduct MSA / Gage R&R Study of tools/instruments which are required to measure & monitor key characteristics of the product, process, or service. For service, identify tools/instruments or equipment which are used to measure, monitor, and control key characteristics.

Step 5: Define preventive maintenance plan of machines including calibration plan of sensor which measures and monitor product and process key characteristics. For service, identify tools/instruments or equipment which are used to measure, monitor, and control key characteristics.

Step 6: Conduct product or process validation and verification to define and deploy design, manufacturing, or service control. Document verification and validation results.

Step 7: Deploy statistical process control to measure, monitor, and control key characteristics. Monitor KC database trend

Step 8: Link key characteristics to TQM (Total Quality Management), Incoming inspection process, in-process inspection, and final inspection process.

Step 9: Deploy mistake proofing techniques in the design, manufacturing process, or in-service protocol.

Step 10: If KC is to be controlled at the supplier or a dealer or service agency, follow the above steps in addition monthly / quarterly KC database control reports/records can be demanded from the supplier.

Step 11: Build the Key Characteristics database by covering all the above requirements and review the KC database on an annual basis at least.

Step 12: Monitor KPI trends of KC database internally and at supplier/dealer and initiate continual improvement if required. Publish KC database control and KPI trends to all key stakeholders as per defined frequency.

Step 13: Link KC database to BCP and Risk management. Do publish KC database.

Key characteristics or special characteristics are essential business factors, which cannot be ignored. Eventually, better key characteristics control in the entire supply chain helps to deliver a safe, reliable, durable, and quality product and service.