Toyota Production System — Lean

The Toyota Production System (TPS) is a philosophy of manufacturing that Toyota credits with its success in producing high-quality automobiles. The concepts behind TPS underpin the lean manufacturing model. The system also relies on manufacturing cells, which were discussed in the prior two sections of this chapter. 

The features of TPS have been copied and modified to fit American companies. Womack and Jones advocate extending the Toyota approach to the entire enterprise, including paperwork as well as product processes. Yasuhiro Monden has documented the TPS. Monden s theoretical model points to two pillars to the Toyota Production System  

Just-in-time. This means producing the right products in the needed quantities at the right time. 

Autonomation. This is autonomous defect control. This term refers to preventing the passing of defective units from one step to another, avoiding the dismptive impact of passed-on defects. 

Both support elimination of the events that introduce variability into the supply chain. Supporting these two pillars are two complementary concepts. One is the flexible workforce. Worker flexibility enables varying the number of workers with the workload and thereby operating with fewer workers. The other concept is creative thinking that encourages workers ideas for improving operations. Both support the flexibility needed to overcome variation. 

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The origins of lean manufacturing are often ascribed to the creation of the Toyota Production System (TPS) by the Toyota Motor Corporation. However, the history of lean manufacturing can be traced back to industrial developments which occurred more than 150 years before TPS. The foundation for modern manufacturing was laid by Eli Whitney in 1798 while Whitney is best known for his invention of the cotton gin, it is his invention of interchangeable parts and uniform production which revolutionized mass production (www.EliWhitney.org). 

During the past three decades, manufacturing underwent many transformations. The primary process evolutions were total quality management (TQM), theory of constraints (TOC), Lean and the Toyota production system (TPS), and Six Sigma, ft will change even further as companies implement the new processes for digital manufacturing (covered in Chapter 6). 

While low inventory levels are a key outcome of the Toyota Production System, the story does not end there. An important element of the philosophy is to work intelligently and eliminate waste in the entire system. The elimination of waste is termed Muda. There are seven commonly accepted sources of Muda in the extended Lean supply chain ... 

Cell design - Cell design is a component of the Toyota Production System, or lean manufacturing. In the cellular shop floor, machines of different types are located together and the focus shifts to the product, not the means of production. In a cellular paperwork process, small groups do all operations. 

The wastes noted above are commonly referred to as non-valued-added activities, and are known to Lean practitioners as the Eight Wastes. Taiichi Ohno (co-developer of the Toyota Production System) suggests that these account for up to 95% of all costs in non-Lean manufacturing environments. These wastes are ... 

Lean Manufacturing is a production philosophy that appeared after World War II. This philosophy is derived from Toyota Production System that was based on Just-In-Time, which consists in adjusting production to demand in order to manufacture just enough quantity to satisfy the order, thus avoiding an unnecessary accumulation of stocks (Suzaki, 1993). 

Lean is the Westernization of a Japanese concept that has carried several names. It has variously been known as the Toyota Production System, JIT (Just in Time), Pull Manufacturing, TQM (Total Quality Management), and other names. Each of these names incorporates some aspect of Lean, and vice versa. What we know as Lean today is not really any of these any more. One possible... 

Agility, as we have said, is not synonymous with leanness but it can build upon it. Leanness in a sense is about doing more with less. It owes its origins to the Toyota Production System (TPS) and its pre-occupation with the reduction or elimination of waste (muda).2 Lean manufacturing is characterised by level schedules , i.e. a forward plan to ensure that the use of resources is optimised. 

Through these innovative practices, Toyota s lean production system formed a complete supply chain from source to user. Its system integrated suppliers and distributors with manufacturing and involved them in product development. In so doing, the lean production model has provided a prototype of the business paradigms of concurrent engineering and supply chain management. For an examination of the implementation of lean production in North American companies, see Liker (1998) and Liker et al. (1999). 

Flow A main objective of the Lean production effort and one of the important concepts that passed directly from Henry Eord to Toyota. Eord recognized that, ideally, production should flow continuously all the way from raw material to the customer and envisioned realizing that ideal through a production system that acted as one long conveyor. 

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