Lean Methodology

Lean Learnings # 6 – Why Takt time must be considered ‘Pure’

Over time I have seen may organisations try and put their interpretation on takt time. Most try to put some form of ‘fudge factor’ into the calculation. This is normally so they can accommodate and ‘efficiency ratio’ or some form of equipment efficiency measure. But why do they do this?

Well most of the time it is because the organisation has completely missed the point of using takt time as a tool. Most understand that takt time is the ‘beat of the customer’, but few really understand that is is also a measure of waste within the process.

It’s also an Abnormality management tool………..

Used properly it is very easy to understand the cost of stoppages, for example, if our production line is planned to run for 40 hours and produce 2400 units (takt time = 60 seconds) but we only produced 2000 units, then we have a loss of 400 units. it is very easy to see we would have to run 400 minutes overtime to catch back. This in turn we can attribute a true cost to.  But the reality is that it makes little sense to add cost to the process in this way. So we have to consider another alternative.


Within the Takt time calculation the key phrase is ‘Available time’. It is quite acceptable  to include ‘Planned down-time’ into the calculation so long as it is planned ahead of time.

So we could choose to build into the calculation and amount of time for maintenance and TPM activities to that when we run the process during the planned up-time we can measure the success of our TPM and maintenance.

This is why companies like Toyota do not generally run 3 shift operations. They choose to spend time each day working on preventative maintenance so that when the bulk of the manpower is on site, the lines run to pure takt time. That way they can look for not only at the quality of the equipment maintenance, but also look for small incremental losses. The trick is to have a very good capture system and have the infrastructure to put into place good countermeasures.

The moment you add ‘fudge factors’ into the calculation you are sending the message that some inefficiencies are OK and you loose the ability to put pressure on the organisation to find and fix its inherent abnormalities.

So before you try to make up your own takt time rules, think about the message you are sending and is there a way you can organise the operation in a different way to drive people to improve and look for small losses.

Everyday examples of Lean

I am always on the lookout for everyday examples of lean that I can use in training courses. I think it really drives home the point that it is possible to use lean concepts in everything we do.

I was in a local restaurant the other day looking at the way the waiters went about their tasks. It soon became obvious that some were more efficient that others. Some had time to chat to the guests, while others appeared to be rushing around. I looked at the number of guests and tables they were serving. That appeared to be in balance. I looked at the various stages the meals were at, again all appeared to be reasonably balanced.

The difference was really was quite simple, some waiters were optimising their movements. Every Time they returned to the kitchen, they would clear a table, or at least not return empty handed. The ones that were running around did not. They were having to make twice as many journeys. One to being food out to the guests and a second process to clear plates. Simple.

So in this case improvement is a simple matter of a little training, yet why had it not been spotted and the waiters retrained?

I think the answer is that we get blind to what we do as we go about familiar tasks. Sometimes it makes sense to stop, watch and understand what is going on.

Supervisors and managers in particular need to make time to observe day to day activities and reflect on simple improvements that can be made. This type of improvement activity costs little, but done on a regular basis can overtime significantly improve processes.

Try it. Watch a familiar day to day process and see what you can see.

‘Selling’ 5S to the workforce.

Anybody that has introduced 5S as a concept to the mass ranks of an organisation will know how difficult it can be.  ‘Another flavour of the month’, ‘another thing to fit in’ and ‘when am i supposed to do this’ are amongst the many cries that can come back. But why is this?

The most common mistake organisations make in introducing 5S is failing to link it to the overall message of Lean and Waste removal. All too
often 5S is introduced as a stand alone program with the workplace organisation as its only supporting benefit.

In this case, it is a difficult sell. Leaving only the precise tools and equipment required in an area to perform a specific task, does not go down well when breakdowns and random quality issues are the norm and little is being done to fix them. The majority of people want to do a good
job for the company and keep the process moving, so it is natural for people to want to keep a few spare parts just in case.

In order to succeed 5S needs to be seen as more that just a house keeping tool. It needs to be linked to the bigger picture and to the overall waste identification process. After all that is what it actually is.

So when you are teaching 5S, explain it in those terms. The 1st and 2nd ‘S’ are aimed at setting the process out in such a way that abnormality can be seen quickly. The 3rd and 4th ‘S’ are aimed at trying to look for deeper issues and how a process can be further improved. And finally the 5th ‘S’ is actually all about the entire organisation working to make the process happen.

Also remember, that when a 5S audit is undertaken, it is not really the score that is important (although it does have a place), it is the small opportunities that the team see to improve.

 

If you would like to know more about 5S why not sign up for the free Kaizentrainer 5S course at

http://www.kaizentrainer.com/Copy-of-5S-Course.html

Or read ‘Tools for success’ By Barry Jeffrey and Graham Ross

http://kaizentrainer.com/

Lean Learning’s #4 Takt Time

Takt time is one of the most important concepts to grasp in a Lean environment, since it is the principle by which the speed of the process is governed.

The word Takt is derived from the German word for beat. In the case of Lean, this refers to the pace of the process as dictated by the customer. If the customer orders 10, then 10 must be produced, not 9 or 11.

The best way to visualise this is by imagining an orchestra with the conductor at the front. He is the customer. The conductor moves his baton up
and down to indicate the ‘beat’ of the music he requires. The musicians follow this beat, all at the same speed, completely synchronized. If he speeds up, the entire orchestra speeds up with him. As he slows down, so do the musicians.

This is the concept of Takt time. A process should adjust its output based on ‘true’ customer demand and not keep running at its maximum speed.

Takt time can be calculated on virtually every task in a business environment. It can be used in manufacturing e.g. machining parts, drilling holes etc. In administration e.g. processing orders, call centre operations etc or in a production line environment, to pace the line.

When implemented correctly, running a process to Takt time provides many benefits. Just a few of these are:

  •  Since you produce only what is required by the customer, inventory is reduced
  •  Since the ‘product’ moves along the process at a given speed, bottlenecks are easily identified.
  •  Since problem processes are easily identified. repeat issues, like breakdowns, can be understood and fixed.
  •  Since the process moves at a fixed speed, work is balanced across all operators. If it is not bottlenecks will occur.

 A lot of confusion can be generated around Takt time calculations. The simplest way of calculating Takt time is to calculate the Takt time for the output of the process. Work from the perspective of the customer.

In order to calculate Takt time, two pieces of information are required.

  • Available Time – this is the shift time minus any breaks, clean up time etc.
  • The Average Customer Demand – how many does the customer actually require in a given period.

Work in fixed periods (days or weeks) and apply the following calculation.

Example

A store card company receives 2,100 applications per month. And on average they work 20 days per month.

Workers are paid for 7.5 hours per day. They have two 15 minute coffee breaks per day – which are paid.

So the Takt time is calculated as follows:

Available time

From the 7.5 working hours 30 minutes must be deducted (for breaks).            7 hours = 420 minutes

Customer demand

2100 / 20 = 105 applications per day

 Therefore the takt time calculation is as follows:

420 minutes   =   4 minutes

       105

So if we were processing applications to Takt time, you would expect to see an application being processed every 4 minutes. Running with a Takt time of 4 minutes means that the process is set up to deal with the customer demand as efficiently as possible.

This Is an extract from the book Tools for Success, by Barry Jeffrey and Graham Ross. If you would like to know more why not follow the link www.kaizentrainer.com

 

 

Lean Learning’s #5 Poka-yoke

The concept Poka-yoke was originally developed as part of the Toyota productions system by  Shigeo Shingo. it is a Japanese term that means “mistake-proofing”.  By interestingly it was originally named “baka-Yoke”, which has the meaning “Fool-proofing”, but this was quickly changed to the less offensive form.

The name is derived from two Japanese words, Poka meaning “Mistakes” and Yokeru meaning “avoid” and really is applied to any mechanism in a lean manufacturing process that helps an equipment operator avoid making mistakes.  Its purpose is to stop the process at the point where a defect occurs. This has two effects. Firstly and most obviously, it stops the defect from being passed on the other processes further down the
line. But also, secondly it allows an error to be investigated at the very point and time the defect originated. This makes problem solving much easier and allows ‘counter-measures’ to be put in place, thus improving quality.

There are 3 main types of Poka-yoke device:

  1. Contact type, which is designed to identify defects by testing the  product’s shape, size, color, or other physical attributes.
  2. Fixed-value type, which is designed to alert the operator if a certain number  of movements are not made.
  3. Motion-step (or sequence) type,  which tests if the prescribed steps of the process have been followed.

Poka-Yoke and its use is not reserved for business. Examples can be seen in everyday life. Here’s just a few:

Fill a car with Fuel. Look at the area around the Filler flap. There are at least 3 examples of Poka-yoke devices present.

  1. The size of the nozzle varies depending on the type of fuel to stop unleaded being put into a diesel. But you can make the error the other way around, so this is not a perfect example.
  2. When you take the fuel cap off, the cap is tethered to the main body, stopping the motorist driving off having left the cap on the roof!
  3. The Cap is fitted with a ratchet to prevent over tightening.

Circuit breakers in houses are designed to prevent electrical overloads . When the load becomes too great, the circuit is broken.

Computer Leads, Look at the back of any computer and you will see a plethora of leads. All of the leads have different type plugs on them to stop them being fitted into the wrong socket.

ATM Machines, return your card before your cash is dispensed to stop you forgetting it. This one works on the basis you are unlikely to forget your cash !!!

In the UK 240v/50Hz electricity is used. This can injure people so electrical plugs are designed so that live electrical pins are never exposed. Two forms of Poka-yoke are used here:

  1. The ‘3 pins’, Live, neutral and earth are positioned and orientated are such that the plug can only fit one way in the socket.
  2. The pins are insulated near the plug body so that electric shock is not possible when the plug is being  pushed in, this also means that if the plug is not fully inserted the current will still pass, but electric shock is not possible since only the insulated portion of the pins is exposed.

Of course there are many more, but I hope this gives you a few examples you can use in lean training courses, or just impress people at a party with your knowledge of Poka-yoke !

Value Thinking

An important aspect of “Lean Thinking” is the idea of Value.Think about your own workplace for a moment which you toil in everyday.

I’d like to suggest to you that there are only three types of activities that are going on.

1.Value Adding Activities 

These are activities that, as the name suggests, “add value” to our customers. A “value  adding” activity is anything we do to transform materials or information into something that our clients require.


Example of value add
 : A caseworker making a decision based on the information presented to them 

2.Necessary Non Value Adding Activities

A bit of a mouthful this one. Basically a “non value adding” activity is something that consumes resources, does not create any value for the client but is still currently necessary to supply the service.

Example of necessary non value add : A caseworker sending out a letter to a client. If everyone had secure e-mail this could be done electronically (but they don’t at present). 

3.Waste 

Waste is any activity that consumes resources, but does not create any value for the client. 

Example of waste : Walking to the other end of the office to get a file 

Now that we have defined the three types of activities that happen in the workplace, I would like you to try this EXPERIMENT.

1. During the day think about all of the activities that take place in your office.
2. Categorise these activities into three list; value add, necessary non value add, and waste.
3. Think about ideas to eliminate the wasteful and necessary non vale adding activities.
4. Implement your ideas.

Hope this helps

Standing in a Circle

Here’s a simple way of getting you team leaders to see the waste in their area, based on a technique used by Taiichi Ohno.

Give them a sheet with the titles of the seven wastes on it.

Draw a circle on the floor with a piece of chalk (or simply make a spot it that’s not practical)

Ask them to turn off mobile phones and radios

Then ask them to ‘stand in the circle’ for 10 minutes and observe the operation, looking for examples of each of the wastes. get them to write down what they see.

Then ask them to come and explain what they have seen. Once they have done this, ask them to fix just one!

Keep repeating this over a few weeks, this will start to condition individuals to look at their areas in a different way. It’s amazing how much they will see.

Simple but effective

Process Mapping software

One of the questions we are asked when running process mapping courses is if we know of a good piece of software for inputting process maps.

The one we would recommend is from a company called Bizagi.

This is an excellent, easy to use, piece of software that is very intuitive and best of all it’s free.

The Bizagi site is full of tutorials and helpful videos etc

With very little practice your will be able to input and edit diagrams, add notes and output into a number of different formats. With a little more skill you can even auto generate reports and other goodies.

The software can be found at www.bizagi.com . The freeware can be found under the products tab and then the download tab.

Develop a Deeper Understanding of Waste

If you are familiar with the principles of Lean then you will be aware of the fundamental principle that there is waste to some degree in every single activity we perform, whether it is at work or in our day to day business.

You will also be aware that in general waste is split in 7 types or categories. Defective products, Waste incurred during transportation,
overproduction, over processing, holding inventory, Waiting and excess motion.

But my question to you is. Did you realise that this is only part of the big picture in understanding ‘waste’ its effects and how to address it.

To  understand this we need to go back a step and really look at some of the core fundamentals of Lean. Let’s start at the very beginning and understand why the removal of wastes within processes is judged so important.

The single most important factor in developing a lean process is the ‘Voice of the customer’. Understanding what the customer needs, in what volume, and when it is needed.

Having understood this, the next step is to develop a system that will deliver to the customer needs on time, to the correct quality, in the right
volume. Sounds simple but this is where the problems start. If the process is not flexible enough to meet the changes in customer demand inefficiencies creep in and hence level of wastes within the process grow.

This is where most peoples understanding (including many lean practitioners) of waste starts to break down.

You may have heard the term ‘Muda’. Muda translated from Japanese is Waste. However this is only part of the story.

When Taiichi Ohno Sakichi Toyoda, and Kiichiro Toyoda, originally set out to develop the Toyota production system, they recognised that the root causes of waste in a process were much deeper than many consider today.

They defined 3 types of waste, MUDA, MURA and MURI

What has happen is that Muda has been given much greater attention since over time it has been well defined into the 7 categories I mentioned earlier.
Because of this, many Lean practitioners have learned to see just Muda they fail to see in the same prominence the wastes of Mura (unevenness) and Muri (overburden). Normally whilst they are focused on getting their process under control they do not give enough time or consider the impact of the other two types of waste.

So let’s take time to consider both Mura and Muri.

Mura or unevenness occurs at a number of levels within a process and needs to be considered when Just in time it being put in place. Consider this, what happens when we reduce or remove inventory (one of our 7 classic wastes). Well, now that the safety buffer has been removed, the process will be put under strain to deliver in a much more responsive way. The entire value chain will be asked to flex up and down in speed. The impact of this change can be devastating to the organisation. Manning levels have to be adjusted (If cost and efficiency are to be maintained), Suppliers will be asked to change deliver schedules at short notice. Maintenance schedules may need changing, in fact a whole plethora of issues arise and all takes time to manage. Also, because of the need to produce at peak volume at any time in theory, equipment, workers, inventory and all other elements required for production must always be prepared for peak production. This is adds both cost and waste.

Unless systems and processes are put in place to do this, waste starts to creep back into the process.

Toyota considered this in the development of the Toyota production system and took it into account with the concept of Heijunka or production smoothing. The concept of Heijunka may at first appear to contradict the Just in time and lean production philosophies, however it must be
remembered that done correctly well small amounts of well managed strategic stock will both aid efficiency and lower overall cost.

In the general concept of Heijunka is to try and smooth the production rate within acceptable limits. There are a number tools and tricks to this which are again linked to the original thoughts behind theToyota production system.

For example. Toyota’s final assembly line never assembles the same automobile model in a batch. Production is levelled by making first one model, then another model, then yet another. The pattern or order of the 3 models is the adjusted to smooth the daily rate based on customer demand (takt time). This flexibility is one of the key reasons for having a mixed model process. But in order to achieve this Standard work must be well defined and implemented otherwise the waste of ‘MURI’ will be the issue.

Muri or overburden, generally occurs when Standard work is not well defined or when addition tasks have been placed upon someone through a process change without consideration to their over workload or line balance.

Within most companies it is the case, but the importance of Standard Work cannot be underestimated. A smooth process with well trained people has a number of other benefits. When everyone knows the standard condition, and the standardised work sequences, heightened morale is seen along with improved quality improved productivity and reduced costs.

So when you are next observing a process for waste, look a little deeper. Look for the all three forms of waste, not just MUDA.

Think of the 3 M’s consider MURA and MURI as well as MUDA