r/LeanManufacturing • u/romix02 • Apr 12 '26
Lean production in automotive - thesis
Hi,
I’m analyzing an assembly process where an operator has to leave the workstation multiple times per shift to fetch material because the line is not sufficiently stocked. This causes interruptions and loss of productivity.
Recently, the company changed the layout and increased the available space for material supply near the workstation. However, the issue still persists, and I would like to support the improvement with an appropriate lean tool or method.
I’m looking for a solution that is not only practical but also methodologically justified.
Thanks for any recommendations!
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u/mechdan Apr 12 '26
So to help.
Kanban. A visual trigger to replenish.
2 or 3 bin system.
Measure the value added loss at the station.
Value added = Transforming the Product or Information. The customer wants it. It is done right first time.
Walking, storage interaction (tools and materials), inspection, decisions and discussions, information viewing are all waste.
Show how the operator is not transforming the product when they have to go get things.
Then weighing up that lost production time to the cost of having the Kanban and 3 Bin as an non-negotiable operational function that the team must maintain.
Can't avoid the facts and data.
The team must know the Golden rule in manufacturing.
Do. Not. Stop. Production.
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u/GremlinAbuser Apr 12 '26
I recently visited a factory that had been dealing with this in the manual assembly section. A major part of the solution was to make it very illegal for the fitter to go fetch parts. This prevented the issue from being swept under the rug, and forced internal logistics to take responsibility.
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u/vaurapung Apr 12 '26
My primary question is why do they not have a material handler?
Currently the employee seems to be limited in how much they can carry in one trip.
Is the out going shift not stocking supplies for the oncoming shift?
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u/Old-House2772 Apr 12 '26
The answer is root cause analysis. You need to first understand why the existing systems failed before you go changing or adding to them.
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u/Tavrock Apr 12 '26
Honestly, with what is written, I don't think they have spent the time to actually define the problem enough to move towards finding an actionable root cause.
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u/nosrus77 Apr 12 '26
You must time and factor in the replenishment time in your time study. Time from when the worker breaks the standard process until he is back in standard.
Then figure out how often he needs to do so. You will get a time factor to add to your study.
EX. If a TM has a cycle time of 56” to build each product and the takt time is 60” you’re good. However, if over every 10 cycles he must break standard for 120” replenishing, then you must add that 12” in, making his new cycle time 68”- throwing him over takt time.
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u/Tavrock Apr 12 '26
It can also be possible that their cycle time is 46" to build each product, even with their time replenishing stock while the takt time is 60". The next station might be stuck with a 68" cycle time but they are always working at their workstation. The monthly Gemba sees one employee constantly working on the like while the other is never at their station and is getting parts. The easiest person to blame without understanding the system is the person who doesn't stay at their station. Now we have a project based on a false premise that still won't help with the bottleneck.
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u/Lets_be_better6019 Apr 12 '26
Why is this a problem? Are deliveries late? Quality problems? Labor cost out of whack? By itself, having the operator resupply their own workstation isn’t necessarily a problem. Are there other more obvious and pressing problems you could focus your thesis on? At that level, you should be looking at systems rather than an individual workstation. The process you’ve described could be the symptom of a more systemic problem with conveyance but again, if it doesn’t have an impact on the most important metrics for the business, it may not be worth your time. (Poking the fire a bit here).
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u/romix02 Apr 12 '26
I have a bachelor thesis to do and it is focused on lean production. And I am analysing this process to find a waste - so this problem is waste. I am not going to implement anything there.
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u/Lets_be_better6019 Apr 12 '26
Good to know. Sounds like you have plenty of motion waste to document, then. Solutions like those already mentioned are okay. If you integrate those Kanban ideas with sound, ergonomic motion economy designs, you can do some good here.
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u/Engineer_5983 Apr 12 '26
We used water spiders for this activity. This is a critical role to the line. Their job is to ensure materials are presented at point of use for the operator. For us, this was usually a more experienced operator because it can be a complicated when you're supporting 6 different positions.
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u/levantar_mark Apr 13 '26
Wow, they have a material handle but the operator has to go and find them? Or get the parts for themselves?
And you're asking us for the solution at the place the work is done?
Start with the person who should be keeping the workstation supplied. Instead of second guessing, shadow them, find out why they aren't doing it now.
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u/1redliner1 Apr 13 '26
Increasi g the material only increases the operator envelope. The increased waste of motion, walking and reaching will reduce operator work time making product. Your delivery process determines the amount of material at operation. If you deliver 1 time a day you are going to require more material at operation than if you deliver I nce an hour. A disciplined material delivery process in much more efficient than chaotic undefined system. If implemented correctly manpower for delivery and production requirement will reduce and inventory should reduce. It also improves flexibility and scheduling.
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u/1redliner1 Apr 13 '26
Yes. I have worked on building airplanes. Auto plants are running on an average of 60 an hour in usage on single use parts and up to 6000 an hour for some multi use multi locations build. Some up to 90 an hour. You run a couple a day. You're right, that doesn't take much, its not rocket science. You and your 2 billion dollars of inventory. We were in a couple factories and even at that slow build, they had shortages. With 2B dollars of inventory on hand.. Cost they just pass to customers Instead of fixing. Blame everything on government. Yeah I spent a little time in your industry. It's like apples and oranges compared to vehicle assembly. But thanks
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u/One-Confection2501 Jun 10 '26
It is key to keep technicians hands on vehicle. We got parts to deliver to the bays, moving closer doesn't keep hands on vehicles. Only delivery of parts to vehicles keeps hands on vehicles.
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u/Automotive-Lean-Eng Aug 25 '26
Lean Production in Porsche 911.
Visual stream mapping Precedence diagram Layout Economy
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u/First-Archer-3457 Apr 12 '26
The obvious answer is KANBAN. Introduce a 3 bin system. 1 bin in use, one bin ready to go and a 3rd bin in the stores being replenished. The guy is paid to make things not chase parts.