ENG - Lean - Dynarax

Lean process 

LEAN MANUFACTURING AND KAIZEN SYSTEMS 

Many business processes and especially manufacturing are based on serial processes, where 

things are passed down a chain of processes, with value being added at each point. Within this 

system there is massive opportunity for inefficiency and waste, such as buffer stores, things 

getting lost, breakdowns, etc. 

A lean system has none of this fat. Going lean means removing all waste from the system. This 

has many implications, such as: 

• Gaining a true understanding how things work so you can constantly improve, reduce 

waste and increase efficiency. 

• Reducing buffer storage to the absolute minimum, which makes everything connected: if 

one point in the system breaks down, everyone is very rapidly also affected. 

• Attention to bottlenecks, including when up-stream to suppliers and downstream to 

customers. 

• Being able to rapidly change the system to work on different products. 

• Having flexible, multi-skilled people who can perform such changes. 

• Having systems and management that engenders such a capable and motivated 

workforce. 

Thus parts and material should arrive at any point just as they are needed, and not before. This is 

known as Just In Time (JIT) and is the perfection that is sought, and can be far more closely 

attained than old systems which use large buffer stores to cover up inefficiencies in the system. 

JIT principles have been adopted in many other areas further afield from the original factory 

floor. For example Just In Time software compilers compile code just before it is needed. 

Toyota is consistently recognized as a leader and originator in this methodology (which helps to 

explain why many of the terms associated with it are Japanese). 

Associated concepts: 

Jidoka 

Jidoka, means, in the production context, not allowing defective parts to go from one work 

station to the next. It specifically refers to machines or the production line itself being able to 

stop automatically in abnormal conditions (for example, when a machine breaks down or when 

defective parts are produced). This Autonomation (as it is also called) allows machines to run 

autonomously, as they will stop when a problem occurs. Ultimately, it is about transferring 

human (or better) intelligence to machines. 

Jidoka is also used when individual people encounter a problem at their work station. They are 

responsible for correcting the problem - if they cannot, they should stop the line rather than let 

the defective part do. 

The principle was first used by Sakichi Toyoda at the beginning of the 20th century when he 

invented a loom which stopped when the thread broke. 

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Poka yoke 


People are human and cannot be expected to do everything like a machine, exactly the same each 

time. A simple distraction can lead to a part of their work being done wrong. It is also not 

necessarily their fault, as poorly-designed processes that require a great deal of attention can 

contribute severely to problems. 

Poka yoke is a Japanese term which simply means mistake-proofing or fool-proofing and implies 

designing work and processes such that it is impossible or very difficult to for people to make 

mistakes. It is a simple principle that can lead to massive savings. 

Thus, for example, a plate that must be screwed down in one orientation only could have the 

screw holes in non-symmetrical positions so that it can only be screwed in the right orientation. 

The principle can be easily used in non-manual situations (where mistakes can have huge costs 

associated), for example in a project management process, checklists may be used at various 

times in the project to check that particular tasks have not been forgotten. 

5Ss of the workplace 

The '5Ss' of the workplace are the Japanese words: 

• Seiri = organization : separate out all the things that are not necessary and eliminate them 

or tidy them away 

• Seiton = neatness : arrange the essential things in order so that they can be quickly and 

easily accessed and put away 

• Seiso = cleaning : keep machines and working environment clean (everyone's job--no 

cleaners needed) 

• Seiketsu = standardization : make cleaning and checking a routine practice; maintain a 

pleasant environment 

• Shitsuke = discipline : standardize the previous four steps and constantly improve them; 

creating good habits 

In a tidy and organized workplace, errors are minimized, work is speeded up and small problems 

are made visible. 

These have been translated (more than once) into five Ss in the English language: 

• Seiri --> sort, structurize, sort out 

• Seiton --> straighten, systematize, systematic arrangement 

• Seiso --> scrub, sanitize, spic and span 

• Seiketsu --> systematize, standardize 

• Shitsuke --> standardize, self-discipline 





Let's leave the last word to Hiroyuki Hirano, author of 5S: Five Pillars of the Visual Workplace: 

"A company that cannot successfully implement the 5S's cannot expect to effectively 

integrate JIT, re-engineering, or any other large-scale change. Good workplaces develop 

beginning with the 5S's. Bad workplaces fall apart beginning with the 5S's." 

Takt time 

"Takt" is the German word for the baton, as used by a conductor to control the speed at which 

the orchestra plays. In manufacturing, takt time is a calculated value that gives the speed at 

which parts must be manufactured in order to satisfy demand. 

To calculate takt time: 

1. Determine the daily order or demand volume. (eg. 21 instruments per day). 

2. Determine the number of time units (often minutes) in a working day. (eg. in an 8 hr day 

with 1 hour for lunch and no other breaks there is 7 x 60 = 420 minutes). 

3. Divide the number of minutes by the number of products needed. (420÷21 = 20. This 

means that one unit must be manufactured every 20 minutes in order to meet demand. 

Takt time thus is 20 minutes.) 

The takt time gives 'production slots' into which products must be manufactured to meet 

demand. 

The other form of time that is important is cycle time, which is the measured time that it actually 

takes to make a product. If this, plus any set up times, is greater than the takt time, then it is time 

for process improvement! 

If you have a totally controlled and synchronized lean system, the takt time of all processes in 

the entire supply chain will be linked, even to controlling when the customers purchase. 

Gemba 

According to Masaaki Imai, the author of 'Gemba Kaizen': 

"Gemba in Japanese means the place where all activities are actually taking place; in 

other words, the place where value is added. In case of the manufacturing industry, 

gemba is the shop-floor; for the hotel industry, it is the place where the food is actually 

being cooked; and in case of the service industry; it is everywhere. Gemba is thus the 

most precious place for the management." 





He thus exhorts managers to 'go to the Gemba'. Gemba also gets used as a prefix for things that 

happen on the shop floor. Imai describes Gemba Kaizen, continuous improvement on the shop 

floor, thus: 

"The key is to be inquisitive. If I, as a manager, notice a leak in one of the machines I must be 

able to track down the problem. I must know that the leak is because of a gap, that the gap has 

been caused by the vibrating action of the machine. And that the vibration has caused two 

specific screws to loosen and cause the gap. The solution could be in tightening those two 

screws every morning before the machine is started. Thus, avoiding the possibility of a leak." 

Another Gemba is the 'Gemba-Cho' is a 'working foreman', a kind of on-the-job teacher, whose job is to 

both do a job and also train other people in the job.

ENG - Lean - Dynarax

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