A simple definition of lean
Lean means doing more with less effort by looking at work through the customer's eyes. Anything the customer would not pay for, such as waiting, rework, extra movement or unused stock, is waste, and lean teams work to remove it steadily rather than in one big project.
Where did lean come from?
Lean was developed at Toyota after the Second World War, led by Taiichi Ohno and Eiji Toyoda, and became known as the Toyota Production System. The word "lean" was coined by researcher John Krafcik and spread through the 1990 book The Machine That Changed the World. James Womack and Daniel Jones then set out its five principles in Lean Thinking.
What are the key ideas of lean?
- Value is defined by the customer. Work that does not serve them is waste.
- Waste is everywhere. The eight wastes give teams a common language to spot it.
- Respect for people. The people doing the work know it best and are asked to improve it.
- Continuous improvement. Small, regular changes, known as kaizen, add up over time.
- Go and see. Leaders learn about problems at the place the work happens, the gemba.
Lean tools and lean thinking
Lean is often reduced to its tools: 5S, kanban, value stream mapping and A3 reports. The tools matter, but they only last when the thinking behind them, value, flow and learning from problems, is understood and practised daily.
Where is lean used?
Lean started in car making and is now used across manufacturing, food and beverage, healthcare, construction, logistics and software. The same ideas apply wherever work moves through steps. See lean manufacturing and lean management for how it is applied on the floor and in leadership routines.
Example
A packing line lost time every shift while operators waited for labels to arrive from a store room. The team mapped the steps, saw that the waiting was the largest delay, moved a small label stock to the line and agreed a refill signal. Nothing was bought and no one worked faster; the wait simply stopped being built into the job.