What is Lean Manufacturing? And What are the 5 Principles?

By Protolabs
Lean Manufacturing, otherwise known as Lean Production, is a concept that has been around for years. But, why is lean manufacturing important? In this blog we explore the history of lean manufacturing and detail the key principles behind it

What do you think of when you hear the term “lean manufacturing”? Kaizen? Continuous improvement? Waste reduction? Lean manufacturing is a production process that originated from Toyota in Japan when the Toyota production system was developed in the mid-20th century.
The ideology of lean manufacturing revolves around the principles of continuous improvement, waste elimination and a customer-centric approach – In short, to maximise value and minimise waste.


Lean manufacturing has “5 principles”: value, value mapping, flow, pull and perfection. Let’s look at each principle in more detail to understand how each step supports the pursuit of a lean manufacturing system.

Value – The first step is to define value. Value is any action or process that a customer is willing to pay for and finds valuable. The customer’s “value” is the starting point, and you should then identify all activities that support these values. Think! What is the timeline for delivering your product/service? What is the price? What expectations need to be met?

Value Mapping – Next is analysing and mapping the entire process of delivering your product/ service. From the initial concept to the customer’s hands. Whilst the customer’s “value” is the starting point, you should identify all activities supporting these values from there. When mapping your values out, you will encounter “waste” in your process/ flow. This waste can be put into two categories: 1) Non-value added but necessary. 2) Non-value added and not necessary.

Category 1 you should be looking to remove from your process immediately!

Category 2 you should work on reducing over time.

Flow – Ensuring that there is a smooth and continuous flow of work through the entire value stream. Once waste is removed, the next step is breaking down each part of your process. What can be done to improve the steps in your process and ensure they flow smoother? This could involve training of employees, adjusting production processes, incorporating robotics and AI etc.

Pull – The ideal is that components are produced as and when the customer demands them. This just-in-time approach to production means less inventory and work-in-process items, whilst ensuring that all required materials, processes, and information are available for a smooth flow of work. This means less waste and increased efficiencies.

Perfection – The final principle of lean manufacturing. This is the stage when all other stages are completed, resulting in reduced waste and a smoother, more efficient process.

Once you complete this cycle, it isn’t the end of the chain. In a true continuous improvement style, we go back and start the process again, which is the essence of Lean manufacturing.