In this post I will give an overview of the Lean Philosophy and cover a few essential topics:
- Value vs Waste ( Ohno’s seven wastes; Non-Value Adding (NVA) and Essential Non-Value Adding (ENVA); and Muda, Mura and Muri)
- Visual Control
- Value-stream mapping and analysis
Lean was initially defined by Womack, Jones and Roos (1990) as an integrated way of eliminating waste in order for every step in every process to add value for the customer. It has five principles that were described by Womack and Jones (1996) as:
- specify value;
- identify the value stream and eliminate waste;
- make the value flow;
- let the customer pull the (value) process; and
- pursue perfection.
The advantage of these five principles is that they give the organisation a road map to more plainly apply the Lean Thinking philosophy to a business process (Haque and James-Moore 2004). Furthermore, these principles also meet the improvement cycle defined by Deming; plan–do–check–adjust (Deming 2000). These Deming’s four steps are used for the control and continuous improvement of business processes, which is identical to what Lean proposes.
Generally, there are two main terms to clarify in order to understand the lean philosophy: value and waste.
Value can be described as something that meets the customer’s needs at a particular time and price, in other words, it is what matters to the customer.
Waste was defined by Fujio Cho, the former President of Toyota, as “anything other than the minimum amount of equipment, materials, parts, space, and worker’s time, which are absolutely essential to add value to the product” (Suzaki 1987).
The types of waste may further be divided into six main types that have been identified in the literature, these types may then be grouped into three broad waste types, which are: (1) Ohno’s seven wastes; (2) Non-Value Adding (NVA) and Essential Non-Value Adding (ENVA); and (3) Muda, Mura and Muri.
1. Ohno’s seven wastes
Firstly, Ohno’s seven types of waste were suggested by Toyota Chief Engineer Taiichi Ohno as part of the Toyota Production System (TPS). These types of waste of an organisation were the following: over-production, delays or waiting, transportation, unsuitable processing, inventory, unnecessary movement, and defects (Ohno et al. 1987).
2. Non-Value Adding (NVA) and Essential Non-Value Adding (ENVA)
Secondly, there are the Non-Value Adding (NVA) and Essential Non-Value Adding (ENVA) types of waste. On one hand, the activities that are Non-Value Adding can and should be eliminated because they do not add value to the customer and are not essential. One the other hand, the Essential Non-Value Adding activities are those that in spite of the fact that do not add any value to the customer cannot be eliminated. An example of the latter could be quality inspection, therefore the organisation should try and standardise, or if possible automate, these activities.
3. Muda, Mura and Muri
Finally, the last group consists of Muda, Mura and Muri. These are often called the 3Ms of Lean (Watanabe 2000) and have the following meanings: Muda (waste or non-value adding actions), Mura (workload fluctuations or unevenness) and Muri (overburden). An interesting fact about these types of waste is that if Mura and Muri are eliminated, then Muda will not be created in the first place. Thus, a business should not directly focus on eliminating Muda but on its prevention by solving Mura and Muri.
In spite of the fact that Haque and James-Moore (2004) considered the use of Lean principles in New Product Introduction (NPI) an unusual endeavour back in 2004, a literature review shows that manufacturing is still the most dominant stage for the use of these principles. However, there are a variety of Lean tools and techniques that can be used to help an organisation identify and eliminate waste as well as reduce the non-value-adding activities in the design stage of an NPI.
Firstly, the 5C which is a five step technique to organise the workplace and is important in the design stage and subsequent delivery of the new product to customers. The reason being that it enforces a continuous improvement of the working environment by not only establishing a standard (Wheat, Mills and Carnell 2003, p. 44) but also by eliminating noise. The 5Cs are: (1) clear-out; (2) configure; (3) clean and check; (4) conformity; and (5) custom and practice. These were derived from the Japanese 5Ss which consist of: Seiri (sort), Seiton (straighten), Seiso (scrub), Seiketsu (systematize), Shitsuke (standardise).
Secondly, visual control could be used in order to check that everything is going according to plan. These should be quick checks that ensure that everything is proceeding as well as it should. Haque and James-Moore (2004) add that these types of visual checks are very productive in recognising areas where complications might occur.
Value-stream mapping and analysis
Thirdly, the value-stream mapping and analysis. It is also known as “material- and information-flow mapping” (Rother and Shook 1998) and is a Lean tool that helps analyse and design the steps necessary for a product to go from the current state to a successful deliver to the customer.
One important point identified by Karlsson and Ahlström (1996) is that it is not enough for an organisation to simply implement the Lean techniques to reach the goal of Lean product development. In order to accomplish that the organisation needs to unite these seemingly isolated techniques as a whole process.
Deming,William Edwards (2000). The new economics: for industry, government, education. MIT press.
Haque, Badr and Mike James-Moore (2004). ‘Applying lean thinking to new product introduction’. In: Journal of Engineering design 15.1, pp. 1–31.
Karlsson, Christer and Pär Ahlström (1996). ‘The difficult path to lean product development’. In: Journal of product innovation management 13.4, pp. 283–295.
Ohno, Taiichi et al. (1987). ‘The Toyota Production System’. PhD thesis.Monterey Institute of International Studies.
Rother,Mike and John Shook (1998). ‘Learning to See: Value StreamMapping to Create Value and EliminateMuda. v. 1.1’. In: Oct., The Lean Enterprise Inst., Brookline,Mass.
Suzaki, Kiyoshi (1987). New manufacturing challenge: Techniques for continuous improvement. Simon and Schuster.
Watanabe, Susumu (2000). ‘The Japan model and the future of employment and wage systems’. In: International Labour Review 139.3, pp. 307–333.
Wheat, Barbara, ChuckMills andMike Carnell (2003). Leaning into Six Sigma: a parable of the journey to Six Sigma and a lean enterprise.McGraw-Hill New York, NY.
Womack, James P and Daniel T Jones (1996). ‘Lean thinking: Banish waste and create wealth in your organisation’. In: Simon and Shuster, New York, NY 397.
Womack, James P, Daniel T Jones and Daniel Roos (1990). Machine that changed the world. Simon and Schuster. Zhou, Jian-Lan, Ze-HuaBai and Zhi-Yu Sun(2014). ‘A hybrid approach for safety assessment in high-risk hydropower construction-project work systems’. In: Safety Science 64, pp. 163–172.