2.5 Model by Jeffrey Liker

Introduction: 2.5 Model by Jeffrey Liker

The 2.5 Model by Jeffrey Liker is a Lean framework that highlights the importance of training and education. It shows that for Lean and Lean Six Sigma to succeed, employees must understand customer value, waste, problem solving, and continuous improvement.

Background

Jeffrey Liker, author of The Toyota Way, developed the 2.5 Model as a way to strengthen Lean learning. Many organisations apply Lean tools but struggle to build the culture behind them. The 2.5 Model addresses this gap by focusing on skill development and awareness, ensuring Lean is embedded in both practice and mindset.

Key Elements / Features

The model focuses on seven core training areas:

1. Customer value – Learning to think from the customer’s perspective.
2. Identifying waste – Recognising the eight wastes and how to eliminate them.
3. 5 Whys – Asking repeated “why” questions to uncover root causes.
4. Root Cause Analysis – Finding the fundamental problem for lasting solutions.
5. Standards – Using standardised work to build stability and reduce variation.
6. Trying solutions – Encouraging a test-learn-adjust cycle to solve problems.
7. Kaizen – Practising continuous improvement in daily work.

Applications / Examples

Organisations use the 2.5 Model as a training framework for Lean programmes. For instance, a hospital may train staff to spot waste in patient flows, while a manufacturer may apply root cause analysis to reduce defects.

Relevance / Impact

The 2.5 Model highlights that Lean success depends on people, not just tools. By investing in training, organisations create stronger foundations for efficiency, innovation, and customer satisfaction.

See also

• Lean Training
• Kaizen
• Root Cause Analysis
• Standardised Work