Voice of the Customer in Lean Six Sigma

Competitiveness is essential for any business today. It is vital to put all your efforts into meeting the needs and wishes of your customers. In Six Sigma, Voice of the Customer (VOC) analysis, a methodology that helps customers communicate their needs, wants and solutions plays a crucial role in this.

Customers are what keep a company alive in today’s market. Customers can be as good or worse than us if we don’t listen.

This scenario of change can be avoided by using Customer Voice (VOC).

How do we define the Voice of the Customer (VOC)?

The Voice of the Customer analysis method grew with Six Sigma. It became very inviting to facilitate the identification of improvement points in an efficient and precise manner, always from the perspective of the customer.

VOC allows Lean Six Sigma to determine which key areas and processes should receive more investment. This has allowed the client to connect their needs and wants with the various processes in the company.

To help me understand my writing better, I listed the four macro steps required to implement the VOC. I also wanted to be able to quantify the relationship between the company’s processes and variables and the customer’s expectations. Let’s see it.

What is voice of the customer?
Implement Voice of the Customer with solutions

In 4 Steps Implement the Voice of the Customer (VOC)

Here are 4 steps to help you implement the voice and wishes of your customer in a Lean Six Sigma project:

1- Learn how to interpret the needs of your customers

Ask your customers what they want. This must be done in the Define phase of the DMAIC process.

You can obtain information about the sales price, delivery, quality, reliability, flexibility, and reliability through questionnaires, interviews, satisfaction surveys, and meetings.

There are two ways to collect this information: reactive sources and active sources. 

Reactive sources when information is sent to you via complaints, SAT Surveys, or a report. However, the information is already mapped and has been obtained via a communication channel. It is now available for you to study or analyze.

  • You don’t have the data you need from reactive sources. You should try to get the information you need through research, interviews, focus groups, meetings with clients, and direct observation.

Customers may be vague about what they need and will sometimes suggest improvements. It is important to translate client speech into technical terms or business terms that are useful for the project.

Once you have collected the information, you will need to translate it into technical terms. 

Critical to Quality (CTQ): These characteristics are critical for determining the quality of a product or service. When a customer refers to a product or service offered to make a claim, it is usually talking about some CTQ.

  • Characteristics of the Process (CTP): These are critical characteristics of the process. CTP is when the customer refers to the process to indicate that they have an expectation or a need in relation to the production process or the administrative process.

It is crucial to collect this information, but it is equally important to organize the most efficient and reliable method of collecting it. An external customer can also be an internal one. Let’s look at the differences.

  • Internal customer: people or areas within the company who receive the intermediate product, service, or finished product. They can often assess the process characteristics.
  • External customer: people or companies who use the products or services offered by the company. They are often able to evaluate the features of the product or service they have purchased.

2- CCR: Transforming needs into requirements

Critical Customer Requirements refer to a process that transforms customer requirements into product or design requirements.

Many companies don’t have Critical Customer Requirements and stop at the first step. They do not want to convert their customers’ desires and needs into product design or product requirements.

These companies base their decisions on this information preventing them from taking the correct action when it is really needed.

The Matrix Quality Function Deployment (QFD) is a very useful tool in this stage. This tool is used to identify the needs of specific customers or just one customer, and then to fulfill the service specifications of the team.

This tool allows you to determine the relationship between your needs and your requirements. You can also obtain information about which solutions should be implemented in order to best serve your client.

3- KPOV: Managing output variables and meeting requirements

Although the VOC might inform a customer that they are unhappy with the delivery time, CCR can determine that the customer’s deadline for shipping their products is between 5 and 5 days. Key Process Output Variables or KPOV will help to determine the maximum Lead Time for these products.

The SIPOC matrix can be used to visualize this relationship between CCR and KPOV. It is possible to see all output relationships and client expectations.

What is the voice of the customer?
What is the voice of the customer?

4- KPIV: Adjusting input variables to meet the needs of your customer

KPOV is where the final performance indicators are evaluated. Key Process Input Variables, or KPIs, are the input metrics. It is not clear if you have noticed, but there has been no improvement.

Once you have been able to determine the customer’s requirements and their service needs, and then obtain the desired output metrics, Six Sigma projects are now ready to be deployed to improve process entry performance. The end result is not affected by the process input.


Competitiveness is essential for any business today. It is vital to put all your efforts into meeting the needs and wishes of your customers. Voice of the Customer (VOC) analysis, the voice of the customer solutions/methodology that helps customers communicate their needs and wants, plays a crucial role in this.