Lean has a very close link to the Henry Ford's early line assembly system at RiverRouge. Sakichi Toyoda's son Kichiro visited Ford manufacturing facility and got the understanding of the concepts behind it and more importantly the problems incorporated to that system. This is a very strong evidence to prove the closer relationship between Ford system and Toyota system.
Although the concepts were developed by the owners themselves in the initial stages, the father of lean manufacturing is considered as Taiichi Ohno. Taiici Ohno says whatever he learned of Lean, it was from Henry Ford. If you read the book "Today & Tommorow" by Ford, you would believe what Ohno said. He understood the principles behind lean and then developed them to suit the requirements of Toyota. Definition of waste, maintaining customer supplier relationship internally and externally, empowerment and respect to people, idea generation and using of ideas generated by employees to the betterment of the organisation, ability to adopt to the fast changing situations, looking into the bigger picture by avoiding sub optimisation, simplicity are among the key features of any lean system.
Today the Lean concepts have reached many other industries including healthcare, service providers and even military. The variety of organisations that are practicing Lean concepts in them goes to show the universal applicability of Lean concepts or Lean thinking. Lean practices may be unique to the implementation but the Lean thinking is universal.
Lean is a conceptual change to the system and not just short term change in the system. This requires lots of change management and care for people. People are the most important resource for any lean manufacturer. If anyone wants to cut down in number of heads it should not be in the name of Lean. Lean is not about cutting corners either. It is about elimination of waste from the system continuously. Many implementations of Lean fail due to the lack of understanding on basic Lean concepts and general knowledge, not because of the problems in lean itself.
Now the Lean has gone over its premises of operations and are now becoming Lean Enterprises. Lean enterprises consist of customers and suppliers of the manufacturer. They help each other in the process of value creation and ultimately getting rewarded collectively for their efforts. Large amounts of wastes do exist in interfaces where each party separated in the supply chain. In today's competitive markets most of the companies are willing to reach their suppliers and customers and treat them as partners not as separate parties.