Phase 1 · Define
Voice of the Customer: how to turn what people say into requirements
The Voice of the Customer gathers what the people who receive a process say they need, in their own words. You then translate it into a few requirements the team can measure, so the project improves what matters to them.
In short
The Voice of the Customer (VOC) is what a process’s customers say they need, in their own words, collected through interviews, observation or complaints and translated into measurable requirements, often called CTQs (critical to quality).
What it is
It works in two moves. First you collect what customers say, word for word: comments, complaints, interviews, time spent watching them work. Then you translate each comment into the need behind it, and each need into a requirement with a figure.
The customer is whoever receives the output of the process, inside or outside the company. In a training process, the new operator, the line that receives them and the person who trains them each have a voice worth hearing.
When to use it
- In the Define phase, before setting the project’s goal, so it rests on what customers need rather than on assumptions.
- When the team disagrees about what a good result looks like for the process.
- Before choosing what to measure, so the KPIs of the Measure phase follow from real requirements.
How to do it, step by step
- 1Name the customers of the process. Everyone who receives its output, internal and external. The last column of the SIPOC is a good starting point.
- 2Collect their words as they say them. Interviews, short surveys, complaints, or time watching the work. Write the comments down verbatim, without interpreting yet.
- 3Group the comments by theme. Comments that say the same thing in different words go together. Sticky notes on a wall are enough.
- 4Find the need behind each theme. Ask what the customer is trying to get. “Nobody tells me anything” often means “I need to know how I am doing”.
- 5Turn each need into a measurable requirement. A figure and a limit: how much, how often, by when. That requirement is the CTQ the project will measure.
- 6Check it with the customers. Show them the requirements. If they do not recognise their own needs, go back to their words.
Worked example
Case: a plant that wants new operators to reach standard output sooner.
| Voice of the customer | Need | Requirement (CTQ) |
|---|---|---|
| New operator: “Every shift someone different shows me a different way.” | One method and one person to learn from | The same buddy for the first eight weeks, and one written work instruction per station |
| New operator: “I never know whether I am doing it right.” | To know how they are progressing | A progress review every week against a skills checklist |
| Production manager: “I cannot plan the line if I do not know when they will be ready.” | A predictable release date | Release to production within 9 weeks, with the date set on day one |
| Experienced operator: “I train them on top of my own output.” | Time set aside to train | Two hours per shift reserved for training, with the output target adjusted |
Common mistakes
- Writing down what the team thinks customers want instead of what they actually said.
- Listening only to the external customer and forgetting the internal ones.
- Stopping at the comment: “better training” is not a requirement until it has a figure.
- Asking leading questions that confirm the solution the team already has in mind.
Frequently asked questions
What is the difference between VOC and CTQ?
The VOC is what customers say, in their own words. A CTQ is the measurable requirement derived from it: a characteristic with a target and a limit that the process has to meet.
How do you collect the Voice of the Customer?
Through interviews, surveys, complaints and watching customers use what the process delivers. Combining two or three methods gives a fuller picture than any one of them.
Who is the customer in an internal process?
Whoever receives the output: another department, the next step on the line, or the employee the process serves. Internal customers have requirements just as external ones do.