Critical to Quality (CTQ) Tree: Lean Six Sigma Tool

What is a CTQ Tree?

A Critical to Quality (CTQ) Tree is a structured tool used in Lean Six Sigma to transform broad customer expectations into specific, measurable process characteristics/parameters. It ensures that businesses focus on what truly matters to customers by breaking down their needs into key drivers and performance metrics.

At its core, a CTQ Tree helps organizations:
✅ Define what customers truly value in a product or service.
✅ Translate customer expectations into measurable process characteristics.
✅ Ensure process improvements align with business goals.
✅ Monitor key performance indicators (KPIs) to maintain high-quality service

Why Do We Need a CTQ Tree?

A CTQ Tree is essential for businesses because customer expectations are often broad, vague, or subjective. Without a structured way to define and measure what customers truly value, businesses may:
❌ Focus on the wrong priorities – Improving aspects that don’t impact customer satisfaction.
❌ Lack measurable quality standards – Making it difficult to monitor and maintain service consistency.
❌ Fail to meet customer expectations – Leading to poor reviews, dissatisfaction, and lost business.

A CTQ Tree helps businesses:
✅ Align business improvements with customer needs – Ensuring customer satisfaction is at the core of process improvements.
✅ Standardize quality metrics – Setting clear performance benchmarks to track efficiency and effectiveness.
✅ Improve decision-making – Enabling data-driven improvements rather than relying on assumptions.
✅ Optimize processes for long-term success – Ensuring a structured approach to continuous improvement.

By implementing a CTQ Tree, businesses can identify key success factors, improve operational performance, and drive customer loyalty.

Understanding the CTQ Tree Hierarchy

A CTQ Tree is structured into three hierarchical levels, ensuring that broad customer needs are transformed into actionable and measurable performance criteria.

1. Need (Customer Requirement)

• The high-level expectation or requirement of the customer.

• Represents what the customer values the most in a product, service, or process.

• Usually broad and qualitative, requiring further breakdown into specific drivers.

💡 Example:
For a hotel stay, a customer might expect “A Great Hotel Stay Experience”.

2. Driver (CTQ Driver)

• Key factors that influence the customer need and contribute to customer satisfaction.

• These are process-level goals that directly impact the customer experience.

• More specific than needs but still not fully measurable.

💡 Example:
For A Great Hotel Stay Experience, the key drivers could be:
✅ Speed (Check-in time, checkout time, response time for guest requests)
✅ Quality (Clean rooms, hygienic food, well-maintained amenities)
✅ Cost (Competitive pricing, discounts, value for money)
✅ Service (Friendly and knowledgeable staff, issue resolution)

3. Process Metric (CTQ Measure)

• A quantifiable metric that defines how well the process must perform to meet the customer’s need.

• The CTQ becomes measurable and trackable at this level.

• Performance requirements are set based on customer expectations or business goals.

💡 Example:
For Check-in Time, the CTQ Measures could be:
✅ Guests should be checked in within 5 minutes
✅ 95% of guests should complete checkout in under 3 minutes
✅ Hotel staff should fulfill guest requests (extra towels, toiletries) within 10 minutes

CTQ Tree Example: The Hotel Stay Experience

CTQ Tree Example

How to Build a CTQ Tree?

1. Identify Your Customers

Define who your customers are.
1. Business Travelers – Guests traveling for work, conferences, or corporate meetings.
2. Leisure Travelers – Guests traveling for vacations, personal trips, or relaxation.

Identify Customers

2. Collect the Voice of the Customer (VoC)

Gather insights through:
✅ Surveys & feedback forms
✅ Customer reviews & complaints
✅ Interviews & focus groups

Collecting Voice of Customer

3. Translate VOC into Needs, Drivers, and Performance Metrics

• Need: The broad customer expectation.

• Driver: The process-level factors influencing the need.

• Process Metric: A measurable KPI to ensure quality.

💡 Example:

• Need: Great hotel stay experience.

• Driver: Speed → Check-in process, response time for guest requests.

• Process Metric: Check-in should take less than 5 minutes, guest requests should be fulfilled within 10 minutes.

By using a CTQ Tree, businesses can ensure that their products and services consistently meet customer expectations, leading to long-term success.

At Lean Six Sigma Success Academy,  we specialize in teaching these principles to help individuals and organizations transform their processes and achieve greater success. Visit our  website to learn more about our Lean Six Sigma training programs and how they can benefit you.