takt time vary by time

Hello rish251974

You are needing to carefully weigh up the options.

If you run a second shift, those workers may be paid an extra hourly rate, because they work either early or late hours.

1. Is each cart and contents exactly the same?
2. Is each cart loaded with product/s according to orders received for that cart?
   
3. Is each cart made ready with orders of variable product/s to be put aboard various different aircraft?
4. Are any of the cart contents perishable = food?
5. Are any of the carts loaded with urgent product/s = Medical, couriermail, or the like?
   

It would be best do 2 sets of database, and weigh up each against the other.

1. Break it down by shift and calculate takt time and corresponding staffing.
2. Leave as is, and check all Staff/Labour/time/s correctly.

Please reply here

Kind Regards....

Hello rish251974

You are needing to carefully weigh up the options.

If you run a second shift, those workers may be paid an extra hourly rate, because they work either early or late hours.

1. Is each cart and contents exactly the same?
2. Is each cart loaded with product/s according to orders received for that cart?
   
3. Is each cart made ready with orders of variable product/s to be put aboard various different aircraft?
4. Are any of the cart contents perishable = food?
5. Are any of the carts loaded with urgent product/s = Medical, couriermail, or the like?
   

It would be best do 2 sets of database, and weigh up each against the other.

1. Break it down by shift and calculate takt time and corresponding staffing.
2. Leave as is, and check all Staff/Labour/time/s correctly.

Please reply here

Kind Regards....

Thanks for the suggestions Sparkstation. They are indeed some of the parameters I would need to consider. I will list some other information as well:

1) objective : determine planned staffing (rough and dirty- that drove me to use takt time)

2) product - a cart with provisions ( blankets, pillows etc.) for an aircraft.

3) customer- the truck that takes these carts to the plane in batches of 3. They obviously will require the carts based on the first earliest arrival of the aircraft.

4) a forecast of aircrafts with their arrival times for the given day that need provisions. This drives the workload and times when the carts need to be prepared.

5) the cycle times to prepare a cart from products off the shelf is what I timed - approx 6 mins for a cart. There isn't much difference between carts required for a 747, 777 or a 767. I would probably use the largest cycle time.

6) Currently two shifts operate to prepare the carts.

I would have to layout the aircraft arrival times and batch them in groups of three. These would then drive my hourly customer demand. Then calculate takt time and come up with staffing ? Let me know your thoughts.

Thanks.

Rish251974,

Do you have the variation of number of planes per day? E.g.,50 to 65? 250 to 273? This gives the maximum demand.

What is the bottle neck (you have one most of the time) in the processes of preparing the carts? What is this particular process time?

To find out the Takt time (Rhythm time), we normally start with the bottle neck process time, this would be the fastest rate of your line unless you lift this bottle neck, e.g. by investing in appropriate equipment. From this bottle neck, you then find out the maximum daily output per "line". From this maximum output, you check with the Maximum demand and find out the number of lines you need! If there is no bottle neck (every processes complete in equal time, highly improbable!), then the calculation would be much easier! That might be enough for answering your question but remember, Lean manufacturing/management is all about soft-skill, there still are other factors that would have serious effect on how good a "line" is!

Let me know if the 6 minute is the total time for different persons to complete a single carts? How many processes (persons or portions of work of equal time span) are there in this 6 minutes? For any specific reason you want to define such work content as a process? Are there machine/equipment to operate? What would be there through put and what is the machine time, labour time, setup time and move time?

Divide this 6 minutes with the bottle neck time and times it with the number of lines that is necessary, this would give you the number of staffs you need.

From these data, you might be able to design an OK JIT/Lean line! There are lots of more things to do to accomplish a good and earning Lean line.

Cheers,

AC Wing.

Thanks AC Wing.

My original thought was to do some lean implementation and then decide staffing numbers. Basic item arrangement etc. and then arrive at a staffing number. Client pressure has pushed me to do some quick "as is" staffing calculation.

First and foremost, a flight arrival schedule is generated at 8 in the morning listing the times at which aircraft will arrive. This schedule varies by day of week. Some days have 14, others 16 , but pretty much 15-20 aircraft a day.

The provision cart is a product prepared manually by the employees. They fill the cart with supplies like pillows, blankets etc. and prepare it based on type of aircraft ( 777,767 etc).

A truck then picks these carts and takes them to the plane. The truck has a capacity of 3 carts. Other products like lavatory supplies etc. are loosely loaded onto the truck. There are no machines involved in this operation.

The six minutes is the time required to complete building a cart ( on average) done by one person.

There are other parallel processess like sorting of used provisions that are brought back by the truck. The workers also perform other such activities.

I am in a quandary as to how to justify staffing numbers based on the workload, which have smaller other peripheral activities.

Please advise.

Rish251974,

Do you have the variation of number of planes per day? E.g.,50 to 65? 250 to 273? This gives the maximum demand.

What is the bottle neck (you have one most of the time) in the processes of preparing the carts? What is this particular process time?

To find out the Takt time (Rhythm time), we normally start with the bottle neck process time, this would be the fastest rate of your line unless you lift this bottle neck, e.g. by investing in appropriate equipment. From this bottle neck, you then find out the maximum daily output per "line". From this maximum output, you check with the Maximum demand and find out the number of lines you need! If there is no bottle neck (every processes complete in equal time, highly improbable!), then the calculation would be much easier! That might be enough for answering your question but remember, Lean manufacturing/management is all about soft-skill, there still are other factors that would have serious effect on how good a "line" is!

Let me know if the 6 minute is the total time for different persons to complete a single carts? How many processes (persons or portions of work of equal time span) are there in this 6 minutes? For any specific reason you want to define such work content as a process? Are there machine/equipment to operate? What would be there through put and what is the machine time, labour time, setup time and move time?

Divide this 6 minutes with the bottle neck time and times it with the number of lines that is necessary, this would give you the number of staffs you need.

From these data, you might be able to design an OK JIT/Lean line! There are lots of more things to do to accomplish a good and earning Lean line.

Cheers,

AC Wing.

Rish251974,

Lean Management

Takt is a German term meaning rhythm, and Takt time is used in lean manufacturing by people like the those from Jc-I-T Institute of Technology, Inc., where they use the term Demand Flow Technology & Business Strategy for lean manufacturing / management. It is a technology applicable to all different business if you used it correctly. Many people who has got used to traditional batch production mentality found it is hard to switch over. I once worked for a company who sent their staff to learn it in a famous Japanese company for 2 years but could not build such a single line! It is not uncommon to find such situation when you try to switch over to this kind of management, you'll encounter a lot of discourages and resistance! You know what happened to that company when I built them the first lean line? They just could not tell the difference, and finally their boss who has good connection with a renowned leader in the business, Dr. Ohm.., brought this Dr. in and he just pointed straight to the line I built and said this was one. The differences are subtle but the results would be profound if done properly. Their boss then told everyone to go copying my line! Many came back with excuses like lean is NOT for this kind of product, or it is good for something but not for the things they were doing. Not much about to show off, as there are a lot of people are doing this, but the theme here is, IT IS ALL ABOUT SOFT SKILL, copying just does not work! Learning the mentality is crucial. We made profit even at the worst business time back years ago! In their annual report for recent years, they have been making loss of billions yearly in their local currency since just a few key figures left.

Lean management is the kind of management that delivery quality offering in shortest possible time at lowest possible cost, by eliminating waste, NOT at the expenses of your suppliers nor that of your employees! And, it should be a business-wide management rather than just a department's operation! The effect would be peanut if it is not carried out at the top level of the business!

Take Time

Coming back to the Takt time you want to find out, make sure you know it is a pull system, so you better start with the demand you are facing! Beware it is the maximum demand you have to deal with, whether it is an hourly rate, a daily rate or monthly demand, make sure you use the maximum demand.

You said it is 15 to 20 planes. Say, the biggest plane takes 12 carts and the smallest planes take only 5 carts, if there would be at least only 2 smallest planes (10 carts) per day, then you should take the rest as all biggest planes, hence 18 of them that take 216 carts per day. Your total demands would be 226 carts per day or 9.42 planes per hour (assuming you work on 24 hours basis), round it up to 10, or every 6 minute (co-incidence) you need to prepare one cart. Hence, one person is enough for the job. Of course, you'll still need other people in doing other things, do you want them be included in this calculations? Make sure this is your maximum rate! If not your calculation would screw everything up! You have also to include parallel processing, e.g. if there are situation that you have to double the output, the you better review the work load and job responsibilities as well, to make sure your employees are fairly load with similar tasks.

Actually, for successful lean manufacturing, people start doing "line" and processes design early during the product conception design phase, so that everything is taken into account. Design for manufacturing(execution) and design for testing is then possible. During the early stage, you always encounters troubles and difficulties and this is what lean management are good at, not just stable products. Whenever there are trouble or difficulties, concerned parties would feed it back and improvements are made and off it go, then this ensures smooth operations at later stages.

In your case, you probably do not have much you can feedback to change. You have to find out the maximum demand. Say if you have to prepare a cart in 5 minutes, then one person is not going to meet the demand, you have to use 2. But, 2 persons full time on the job would cut the process time (the takt time in this case) to 3 minute (assuming the job can be spread out), then there would be surplus time, then you have to readjust the work content to probably include other work load. Once you figure this out, it is simple and you'll have a balanced line! There are far more to do if you want a genuine and really earning lean management system.

If you want it a success, make sure you don't make your labor work like hell, morale and devotion to work is important and they would only provide these in the form of professionalism under encouragement!

Consultancy may help and I don't mind to give more answer, if time allows.

Good luck!

AC Wing.

Lean management is the kind of management that delivery quality offering in shortest possible time at lowest possible cost, by eliminating waste, NOT at the expenses of your suppliers nor that of your employees! (But at the expense of your customers.) And, it should be a business-wide management rather than just a department's operation! The effect would be peanut if it is not carried out at the top level of the business!

In other words, tell it to Home Depot.

(But at the expense of your customers.) Only if don't even know how to do it! If you found yourself in such situation, do even bother to think of it!

Check operators in the same business, like car manufacturers, who gives you better quality and price? Those who can really adapt to this soft-skill, with the proper mindset and idea always deliver better quality, at better price (taxation is another problem)!

If changes are made superficially without really changing the mentality, then it would ends up in the situation you claim! In any case, those who cannot do adapt always complain!

AC Wing.

long with this, maybe a gantt chart will assist in the manning issue?

Thanks phoenix911.

Could you elaborate on this. I will do some research on this on my own as well.

Rishi

long with this, maybe a gantt chart will assist in the manning issue?

Rish251974, You are using many tools, I would suggest that these tools may be over complicating this. The time to prepare the cart (6-7 minutes) is probably trivial compared to the time to deliver the cart to the extreme delivery point. also simultaneous or overlap demand will require additional staffing.

Rather than takt time (modern way) you should first determine time study for each delivery gate, tabulate frequency at each gate, and calculate number of simultaneous deliveries during normal conditions. Then estimate how frewuent Non normal, ie delays causing additional simultaneous deliveries are due.

Finally what is the worst case of overlapping demand for simultaneous deliveries.

A spaghetti diagram will help remind you that for each delivery, they have to return with a cart and so the time is double for transport...

The overriding factor for this decision is not necessarily your cost penalty, as much as it is the loss to your customer when your crew fails to show up with the comestibles.

Simplify your thinking.

"Lean methods are perfectly adapted for a world where nothing goes wrong."

Is that the world your people are working in?

You asked: Also, is it really bad if they make carts and store it. Does it really have to be produced when needed ? If it is standard provisions (no difference) between flights, probably not, but if the flight coming back from vegas has different needs (more booze or more crying towels lets say, then you would have waste undoing your prepared cart to hit the cartprovisions they order. I would look at the distances travel and then justify having two provisioning stations based on making more of your people time available than i would anything else, based on my experience in major airports.

milo"look at the entire time involved, in the cycle, not just the first half."

milo

Oh Rish251974,

I nearly forget to tell you about the Kanban which you have to find out the size and that would be stuffs you'll prepare before use, and after each day (unless you work on 24 hours basis), you clear them all and started anew each day.

Kanban is a signal for pull, for refilling, and a buffer as well. There are different kinds of kanban, but you most probably use the buffering kanban. These are the tools, coupled with working hours, flex up and down stream, you use to control the synchronization and fluctuations.

Good luck with your installation, I may not be able to connect the next few days, if I can be of further help, please write to my email: awcchang@netvigator.com, where there are people would check for me!

Cheers,

AC Wing.

If one reads between the lines in LEAN teaching, I would say there is nothing necessarily wrong with storing your carts. LEAN teaches inventory is bad, but that Kanbans are good. They are both inventories. The second just helps eliminate bottlenecks by minimizing the start up times once the process is initiated. Also, if you have unused floor space that you have no existing plans for, then what harm is there in having a little extra inventory as long as you know it will be moved within a reasonable time.

As far as TAKT time, isn't that a more useful tool once the process has been developed and operating? It would be more useful to value stream map your process initially and determine where your waste is.

Whenever I've developed a high or low volume process, I've started by determining the cycle time at which I need to produce the product. For instance, if I have a customer that requires 500,000 parts/year and I determine that I need to produce a part every 13 seconds, I will lay out my process so that I ensure each station can complete its task and deliver to the next station within 13 seconds. That doesn't mean I hold it there for the 13 seconds, but that I "must" have it in position of the next station within that amount of time. If a particular operation requires longer time such as curing, then use a kanban (inventory or batch) system to initially accumulate enough product to maintain the cycle time once the process has began.

I've always taken TAKT time as a means in 'rating or monitoring' the system as it is running, but not as a means to develop the system.

There is wisdom in your post.

It appears that we are aligned in our thinking.

My concern is that the poster really hasn't mapped his Demand adequately, nor the true length of delivery process. (much walking/ trucking to far gates, etc.)

Thanks for sharing your experience.

milo

I am NOT surprised to see this kind of mentality and it really happened pretty often. Actually, I expected that. Although people uses a lot of Lean management/manufacturing terms like takt time, but many of them really don't even grasp the underlining principles.

"LEAN teaches inventory is bad, but that Kanbans are good. They are both inventories."

"what harm is there in having a little extra inventory as long as you know it will be moved within a reasonable time"

According to these statements, kanbans are actually inventory in batch production, and there will be NO harm for creating such inventory?!

Lean manufacturing would rather emphasize producing parts only when they are needed. As I said already, it is a pull system, nothing should be done until it is pulled, i.e. the in-process kanban is not filled (parts being used in a first in first out fashion).

The practical reason is that, there other processes in the Lean management to guarantee things are done right or they'll be corrected immediately. So when a part is produced, it would be consumed "almost" immediately. By the time it is consumed, the customer, internal or external, when using it, would know if that these parts are done right or wrong. If it is wrong, say it would NOT fit, then this customer would immediately feed back the trouble and return the parts so that before the supplier, internal or external, carries on with making more junk parts, they have chances to correct it. This therefore eliminates the traditional batch production problem of making a whole lot of junk and be rejected, and have to be repaired, wasting all the human and material resources, time and overhead. This is why Lean manufacturing can provide better quality at lower cost (of course, this is not the only way in Lean to guarantee better quality)! (I hope this also let the Guest who claimed "at the expense of the customer" understand now, how could Lean management/manufacturing make things better at lower cost)!

With these pictures in mind, you all should know now, Kanban is different to traditional inventory in the way that, kanban has limited size, would only allow you to make very small amount, so that even if there are quality issue, you'll be alerted the first moment, wound NOT have to rework a lot. Kanban is also a control to the previous process, when filled, the "supplier" must not carry on with production. Apart from as a guarantee for eliminating bottleneck, Kanban actually have far more functionality, some I've mentioned previously and I am not going to elaborate further, or this post would end up like a book of few inches thick.

"LEAN teaches inventory is bad, but that Kanbans are good. They are both inventories."

I do not invent Lean management/manufacturing, this Japanese spirit did not teach people to discriminate inventory. Technologists, engineers, please stay firm with the spirit of looking into fact and data rather than like politicians!

"what harm is there in having a little extra inventory as long as you know it will be moved within a reasonable time"

What if you build 2 days inventory of carts, but rats or cockroaches found the towels lovely beds to stay in and nice food to chew, what if there sudden needs to change the type of towels to use...

To know Lean management/manufacturing, it takes more than just talent (I am sure that Sonave Sunsets has), patience and care are also important. It is a subtle subject, that a little of this and little of that matters. Do we call these wisdom collectively?

Rishi,

I've answered your email and if there are more I can help, you are welcome. When I find time, I'll answer, I promise.

AC Wing.

Do you ever get out of the classroom? A perfect example of someone lecturing the theoretical without the cognizant ability to adapt their teachings to real life situations. This is what I've been taught make it happen damn it! You obviously weren't capable of grasping the point I was making.

Please explain to me in your infinite wisdom and vast knowledge of LEAN, how you would ensure a one part flow when the process requires encapsulating an electronic board in a 24hr room temp cure potting compound? Don't tell me you would set up a que for rat's to nest in.

Here is another scenario for you in regards to JIT ( Something that was very pratical in Japan where your suppliers were initially all in a country the size of Oregon);

Key supplier is located 3000 miles away and shipment is delayed 24 hours thus delaying your production by as much. At the same time you have a customer that demands on time deliveries and will charge you $10k/min for every minute their line is down. Would you be willing to stick to you're stingent beliefs and pay the penalty or would you adapt your beliefs to the situation in order to ensure on-time delivery?

If you can solve those issues without have to adapting your beliefs to work in a given situation than your right, I don't grasp the underlying principles. Otherwise get of your Ivory Tower of LEAN philosophy and join the real world in doing what it takes with whatever tools are available to make a quality product for your customer while making your company financially successful.

Just as Bruce Lee believed in 'The Art of No Art', that no one art was best. One must choose the 'Right' set of tools that make their specific situation the most successful.

You are right in the fact that you really don't even know what Lean is. If you want to learn to be lean, be polite! The ability to look into subtle details really needs patience, care, understanding, emphathy... collectively termed wisdom!

Whatever you mentioned are all encountered by industrialists in industrialized countries and cities! Do they all give up? Japanese have serious traffic jams, far away suppliers... They managed to solve them all though! You said you read between lines, but you just could not. I have the same troubles you mentioned but I just manage to earn decent profit using lean! Engineers and managers I trained are all earning decent profits using this great practice in the really world! Can't you?

Go back to you inventory building up philosophy, build as much as you like, tell you boss that is practical solution and be happy to state with it, no bother at all. Just don't pretend that's lean!

After all, just change your mentality, you are not far away! It's a shame that you could not stick to proven working principles and practices. There can be NO achievement if there is no believe!

AC Wing.

You need to create a VSM (Value Stream Map) of these carts of provisions. This is the best tool of Lean for planning. You make a current VSM you get all the process needed to complete a cart with all the information of (inventory, man power, cycle time, changeover time, uptime, shift.…) also the takt time = Net Available Time to Work eg. [minutes of work / day] / Total demand (Customer Demand) eg. [units produced / day]. This number takt time vs the average of complete process time let you know if you can meet the customer demand and identify areas for improvement. Then you make a Future VMS with the improvements Kanban for inventory level control, SMED to reduce changeover or a Kaizen event…. Any lean tool can use in order to create a continuos process flow eliminating waste or muda and improve process that not meet the takt time.

____________________

Lean is not a one shot project is a culture of continious improvements.

GWebMedia.net

It would be fair to let those who really want to know lean, that building up inventory in as uncontrolled manner is actually

tying money up in unnecessary stocks,

risking to waste the money in reworks,

worsening the inventory turnover, cash flow and running cost;

while potential quality cost includes that of lose of customers.

People who are not involved in the management level might don't even have an idea how much these means. It can mean billions!

Like it or not, genuine practitioner would know now what is the problem with "what harm is there in having a little extra inventory as long as you know it will be moved within a reasonable time". Just wonder what would happen if your employer really come to know that!

I was trying to tell more about how to deal with situations where people don't know how to deal with delays..., but with the arrogance and impolite attitude, I just don't think there should be more to tell. Figure it out, these are the problems we all solved in the real world where people once said "really?".

Oh if my comments make you feel shame, feel free to rate it off topic! There are so many others reading CR4 forum who understand the subject though!.

AC Wing.

AC WING/ Guest

Actually the critical issue is that the original poster is looking solely at takt time ( a supply Parameter) without having demonstrated that he understands the DEMAND. Having not mapped the process, I suggested Spaghetti charts, So that the poster could understand that the constraint likely is delivering the darn carts, not stocking them. I used term spaghetti charts, As I actually have done this work in my management and operatingpractice and also, been in many many airports, so i applied my experience (as well as lean teachings and critical thinking)

Others use the term values stream map, and i have no gripe with that , but to provide a useable answer at the level of the original post, I stand behind the spaghetti map as useable advice.

Inventory is a waste, but there are situations where it is less of a cost than other solutions to meet the peak or episodic demand. I took an excursion from traditional lean and developed a concept of statistically based predictable production in my steel mill experience where the amount demanded was usually small to a single customer (5 tons) in a single period, but still had to be made in 180 ton original melt batches,and 40ton rolling batches.

Kitting and prestaged carts with packaged goods prepped and waiting for perishables to be installed at moment of need would be a reasonable solution in view of possible contraints that we all know exist in the original scenario, but were not explicitly stated.

your enthusiasm for lean is commendable, but your insistence that inventory is totally evil and a deal breaker regardless is not warranted in this case until we have a better grasp of the facts.

Yes unneeded inventory is a waste. But I would rather have that waste, than a waste of time or movement, which are unrecoverable.

There is a place for orthodoxy, but realities of practice often makes such pure positions untenable.

milo, "Yes, i do realize that the biggest deterrent to excellence is Good"

Milo / Guest,

Inventory and Kanban

Let me make it crystal clear, I never say inventory is evil, but building up inventory in manner of "what harm is there in having a little extra inventory as long as you know it will be moved within a reasonable time" is not lean and Kanban is different to inventory in the way that,

kanban allows people build them up only when they are needed,

only in quantity that are carefully calculated,

in a controlled manner,

inventory in so built must be used in specific way to make sure there is no quality problem, and

normally cleaned everyday,

that has benefit as I mentioned before.

Even if so, kanban must be controlled as I stated, to avoid "harm" of having "extra inventories". Not going to repeat again.

The original poster did state his constraints, that he wanted

Lean implementations,

use the Takt time (which is NOT exactly equal to process time),

to find out staffing needs.

He also wondered if he should build more "extra" inventories,

"

My original thought was to do some lean implementation and then decide staffing numbers. Basic item arrangement etc. and then arrive at a staffing number. Client pressure has pushed me to do some quick "as is" staffing calculation.

First and foremost, a flight arrival schedule is generated at 8 in the morning listing the times at which aircraft will arrive. This schedule varies by day of week. Some days have 14, others 16 , but pretty much 15-20 aircraft a day.

The provision cart is a product prepared manually by the employees. They fill the cart with supplies like pillows, blankets etc. and prepare it based on type of aircraft ( 777,767 etc).

A truck then picks these carts and takes them to the plane. The truck has a capacity of 3 carts. Other products like lavatory supplies etc. are loosely loaded onto the truck. There are no machines involved in this operation.

The six minutes is the time required to complete building a cart ( on average) done by one person.

There are other parallel processess like sorting of used provisions that are brought back by the truck. The workers also perform other such activities.

I am in a quandary as to how to justify staffing numbers based on the workload, which have smaller other peripheral activities."

Sparky did ask if there were perishables, but he did not state. If there are perishable, my view is, building inventory would mean letting inventories stand by and once perishable available, the "FG" can be delivered immediately. But, this is only possible when the inventories are quality fit to use. As mentioned previously, staging, transportations("movement")... are all mudas that would introduce quality issue. This is one of the reasons why lean management does not want inventory built up until it is necessary and consumed "immediately", i.e. no "extra inventory". If the built up inventory found faulty when the perishable are ready, chances are perishable would have to wait for re-work, or re-start of the inventory building line(s), perishable gone bad... It also would waste time, movement that you said you did not want. On top, there are wastes in running cost, quality cost...

After all, you are saying that you met situation that the start up quantity and rolling quantity exceeds normal ordering quantity, and in the name "excursion", you returned to batch production rather than solving them using lean technologies. Actually, I seen this a very common problem with manufacturers, and I also seen people tackling them nicely using lean. Steel mills are different? Judging from what had happened, I believe the German had done something that solved your problem (but I haven't followed this up). Look around, there are many daily examples that things you might once think purely theories is in practice!

I know the pressure of meeting things in unchartered arena and there is not much available information to help striving on, returning back to things once mastered is always appealing.

No matter how you put it, batch production is batch production. Whichever technique or technology it is, you are free to use them, whether it is batch production or lean; and whatever tools you want to use, whether it's spaghetti charts or product synchronization with inverse tree of individual processes (the purpose of application might be a bit different but the latter would be a simpler approach for the original poster's situation)..., be my guest!

But mixing them up would just loss the original poster's perception, especially with the potential pros and cons. This is why I made the use of kanban explicit, and what harm are there as long as inventory building up is concerned. Provided if your employers are OK with that and you are happy with them, there is not bother at all!

You are not the only one who has the impression of "these tools may be over complicating", and I believe many people are capable of figuring out solutions using lean teachings, the only trouble is this really are subtle things that push people's patience, emotion quotients, understanding,... to limits. Once figured out, they are simple!

I don't want to put engineering stuffs in political way, that only confuses things and complicates problems (most of the time). I know nasty words but they don't help solving problems. I was to tell how to solve you starting quantities, rolling quantities problem, but you missed it. My consultant friends are actually complaining that I am giving too much away, although I've already tried to make things less explicit.

Obviously you've done a lot in manufacturing and engineering, might contribute brilliant things in the arena as well. Yet, the world is big enough for reality that you and me might have left out!

AC Wing.

For every hundred steps you want to put forward, you advanced only half when you take the ninetieth step. Pre-matured self-content, prejudice, can't be bothered... all hinder/undermine breakthroughs.

AC Wing,

It has been interesting to read all the comments by other folks. I acknowledge the fact that I don't have much experience in this field and the intention was to figure out the best possible approach. I did have to do a quick and dirty analysis for my clients. It is unfortunate that all that they are concerned is with band aid approaches. This will invariably end up as another project 6 months down the line. There will be another effort launched to figure out appropriate manpower. Due to time constraints to deliver results, there will be stuff thrown out there without any realistic work done.

My dilemma was to do a thorough job but put enough scientific analysis behind it. Then I have the top leaders asking a quick and dirty method to be done. Then there is the Lean Six Sigma approach that I was taking to work towards a Green Belt. I still didn't think that a staffing reduction really requires a DMAIC approach. BUt eventually I did the spaghetti, time studies and demand analysis. The spaghetti did reveal a lot of wasted motion, but rearranging would probably result in a few minutes saved in building a cart. A lot is to do with attitude of front line. Managmenet also doesn't really seemed to buy into the DMAIC approach. But anyways, I did come up with total time taken to build carts for the given day and suggested number of people required and the shift patterns. This did result in showing a substanial savings. I'm sure the vendor will then be pressured in doing the job for less now ! I'm still interested in seeing what approach others would have taken. Let me know if anyone needs some data on this.

rish251974

AC WING/ Guest

Actually the critical issue is that the original poster is looking solely at takt time ( a supply Parameter) without having demonstrated that he understands the DEMAND. Having not mapped the process, I suggested Spaghetti charts, So that the poster could understand that the constraint likely is delivering the darn carts, not stocking them. I used term spaghetti charts, As I actually have done this work in my management and operatingpractice and also, been in many many airports, so i applied my experience (as well as lean teachings and critical thinking)

Others use the term values stream map, and i have no gripe with that , but to provide a useable answer at the level of the original post, I stand behind the spaghetti map as useable advice.

Inventory is a waste, but there are situations where it is less of a cost than other solutions to meet the peak or episodic demand. I took an excursion from traditional lean and developed a concept of statistically based predictable production in my steel mill experience where the amount demanded was usually small to a single customer (5 tons) in a single period, but still had to be made in 180 ton original melt batches,and 40ton rolling batches.

Kitting and prestaged carts with packaged goods prepped and waiting for perishables to be installed at moment of need would be a reasonable solution in view of possible contraints that we all know exist in the original scenario, but were not explicitly stated.

your enthusiasm for lean is commendable, but your insistence that inventory is totally evil and a deal breaker regardless is not warranted in this case until we have a better grasp of the facts.

Yes unneeded inventory is a waste. But I would rather have that waste, than a waste of time or movement, which are unrecoverable.

There is a place for orthodoxy, but realities of practice often makes such pure positions untenable.

milo, "Yes, i do realize that the biggest deterrent to excellence is Good"

Rish251974,

Welcome to the party and it is nice to know that you achieved your task. There are many tools and aids you can use, some makes things simpler at certain situations. Properly done lean can help saving a lot and the nice thing is, the saving does not necessarily cause lose of jobs!

Lean and Six-sigma are usually trained separately back about 10/20 years ago and they are always put under the name of lean-sigma these days. Do they train you separately?

As a Green Belt to be, you should have nothing to fear, just go to your Black Belt / Master Black Belt for aids, helps and resources (they should give you these helps theoretically, but it all depends on how they...)! The great thing about Six-sigma is they have all the robust tools for analysis and if trained properly, you should also have your very practical training that lead to you understand the use of many of such tools, Cp/Cpk, DOE, FMEAs, 7Q tools... are some of the useful ones you would encounter in your Green Belt training. But lean are different though!

You normally spots chances of improvement using lean tools to categorize work as value-adding or non-value added. Depending on how you define you objective and targets of DMAIC projects (When you define your target say, improve the labour efficiency, then you might want to measure the head-counts, material inputs and FG outputs... and so on, analysis might lead you to reduce the head-counts and in the improvements processes, you might take such actions, and you'll control the concerned data from then on), there can be situations of using them to cut labor!

Good luck with you training and certification!

AC Wing.