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.
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.
I think most people have, if there honest with themselves, But why should this be, after all 5S can only help the workforce can’t it?
I think the truth of the matter, like most aspects of Lean, it is down to local culture and how the tool is deployed. Reading a book and then going out and implementing 5S really is not the way.
5S will only work if the workforce believes in it as a tool that is useful to them. This means taking time to explain in detail the reasons why 5S can HELP people.
You need to take time to explain that 5S is a waste identification and removal tool, and is there to help find waste at a local level.
In training it needs to be linked to the 7 classic wastes. 5S must not be seen as a house keeping tool, or something that is done when there is a visit. How many times have you heard, ‘Quick the Big Boss’ is visiting today, give the place a quick 5S!’…….Wrong message.
Time needs to be put aside to work locally with the teams as they deploy 5S in their areas. Not just send the middle managers and team
leaders out with audit sheets.
Audit sheets and there use can be one of the ‘make or break’ aspects of how 5S is received. Explain that the score is not the most important
box on the sheet. That honour goes to the area of the form that say’s ‘Opportunities for improvement’. Teams should try and identify just one or two opportunities at a time and work to improve them. They will then see their scores improve over time. If this is not done, the audit form can become divisive and 5S will start to receive a bad name.
So, 5S, Great tool, make sure it is understood in your organisation!
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.
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