Lean concepts like Value Stream Maps, 5s, SMED, Flow or Pull have become so popular that many people assume that Lean manufacturing equals Just in Time. This is a huge simplification. Just in Time is a very important part of Lean Manufacturing, but not the only part, and it needs many other components to work.
Lean Manufacturing (or Toyota Production System) is commonly explained using the picture of a house that represents how the different parts of TPS work together. This is one example by the Lean Enterprise Institute (http://www.lean.org/):
The house explains the key ideas of Lean manufacturing: The goal, the 2 main pillars and the basement. Please, take your time to read it. You will notice that Just in time is one of the pillars, without it Lean won’t work, but Just in time is as important as Jidoka (Intelligent automation), Heijunka (Balancing), Standardized Work (Procedures) and Kaizen (Continuous Improvement). The VISION (Goal) is definitely the most important part of the house, because if you don’t know where you are going, nothing else matters.
Let’s get some more detail from the house components:
- Goal: Become competitive (Quality, Delivery, Cost) through customer satisfaction.
- Just in time: Providing the right product in the right quantity at the right time
- Flow: Moving products through a production system without separating them into lots
- Pull: A method of production control where downstream activities signal their needs to upstream processes
- Takt time: The available production time divided by customer requirements
- Jidoka (Built in quality): Providing operators or machines the ability to detect when an abnormal condition has occurred and immediately stop work
- Standard work: Documenting the work sequence paced by takt time, the positioning of equipment, standard work in process and various quality and safety checks on several documents and then follow this routine until a better standard is found
- Heijunka: Leveling the type and quantity of production over a fixed period of time
- Kaizen: Continuous improvement of an entire value stream or an individual process to create more value with less waste
Please be aware that Lean Manufacturing is not the same as The Toyota Way, but the concepts are close enough to be easily mixed up. The Toyota Way refers to the management principles of Lean, which can be summarized as:
This is a great post by Michael Ballé showing the difference and sharing his insights: link
Pictures from: http://www.lean.org