How do we make a Pull System if operations are in different buildings?

[William G]

I have implemented Lean in many locations, but I must say that I have been spoiled. All of my locations have allowed me to move the operations within a few feet of each other and create a visual pull systems quite easily. Now I am on a job where the operations are performed on very large machines and they are arranged in a traditional functional layout, ie. one department per building. While I have many ideas on how to create a visual signaling system to create my pull system. I would like to know from those with the same issue, how you are doing it, and how successful it is? eventually with time and lots of money to move everything, I will create cells.

Thanks
William

 

[Wes Bucey]

Re: How do we make a Pull system if operations are in different buildings? your comme

Do machines all do the same function or different functions? If same function, do they run a different rates? If different functions, then separate "pull" for each function seems reasonable. If same function, same rate, then "pull" should be relatively uniform for process as a whole. If same function, different rate of production, then I would first want to know WHY different rates. If rates are intrinsic because of age or size of machine, then each machine needs its own pull, keyed directly to the supplier, regardless of whether they are on same campus or located in different countries.

The basic error many folks make with a pull system is funneling it through a bottleneck central purchasing/ordering department instead of empowering each line to pull as needed against a blanket order from the central purchasing function (central function pays the bills!)

 

[duecesevenOS - 2009]

Re: How do we make a Pull system if operations are in different buildings? your comme

We have multiple buildings here. Quick question/clarification: Are you saying that you might actually go back and forth from building to building? If they are split up by operation will you do operation A in building A then do operation B in building B and then actually go back to do operation C (similar to A) in building A? If so that is a really crazy flow path.

Our facility will do the first few steps in one building and then move to do the next few steps in the next building and so on.

All of the same rules for kanbans apply for moving from building to building. We usually compensate by having two different kanbans to deal with the moving of product. In a sense, you have to treat the move as another operation (and it should have it standardized procedures like everything else).

So you have a supplier in building A that will build to his/her kanban within the building. The customer for building A is actually the transporter moving the product from building to building. The transporter is the supplier to another kanban in building B. So building B simply pulls from the kanban in their building. If everything is treated like another step in the process than everything is seemless. Building A fills it's kanban, the transporter fills their kanban, and Building B keeps well supplied in order to fill their kanban.

 

[William G]

Re: How do we make a Pull system if operations are in different buildings? your comme

thanks duecesevenOS and Wes

Each building has a machine which performs a different function. they machine large parts. So, building 4 forges the metal in to shapes close to the finished size, in bldg 3 they machine out the parts, bldg 2 the drill the holes, bldg 5 has CENTERALIZED INSPECTION So all parts to go building 5 BEFORE going to the next operation. So yes, the parts go back and forth all day long!!!

I like DuecesevenOS solution, I will have to assess floor space, 100 part numbers and parts 14 feet in dia will require a lot of Kanban space.

 

[wmarhel]

Re: How do we make a Pull system if operations are in different buildings? your comme

duecesevenOS makes some good points. The whole purpose of kanban is when operations can't be connected.

The goal of any system should be to make the process flow. The order from best to worst from a material movement standpoint is:

1) Flow - all operations leveled and connected

2) FIFO Flow - operations connected but not all leveled so a build-up of inventory (very small ideally) occurs where imbalances are present.

3) Kanban - the use of a "signal" to notify that more materials are required

4) Batch and Queue - traditional method with materials only being moved by batches

The same thought process should go into value-stream mapping. There is a tendency to slap supermarkets between operations instead of digging down and addressing why the supermarket is needed in the first place. Supermarkets and kanbans should be intermediary steps, this would be especially true given that the issue resides within the company versus having to deal with an external supplier.

Wayne

 

[Wes Bucey]

Re: How do we make a Pull system if operations are in different buildings? your comme

thanks duecesevenOS and Wes

Each building has a machine which performs a different function. they machine large parts. So, building 4 forges the metal in to shapes close to the finished size, in bldg 3 they machine out the parts, bldg 2 the drill the holes, bldg 5 has CENTERALIZED INSPECTION So all parts to go building 5 BEFORE going to the next operation. So yes, the parts go back and forth all day long!!!

I like DuecesevenOS solution, I will have to assess floor space, 100 part numbers and parts 14 feet in dia will require a lot of Kanban space.

It appears that even a rudimentary spaghetti diagram would show Bldg 5 as a potential choke point.

I certainly can't imagine an inspection station as being a "pull" station. No one will build more parts just because inspectors are idle - only the next process will provide the pull. The alternate is to let Bldg 5 be an inventory storehouse - they can't send inspected parts to the next station unless that station has finished the previous one and is ready for the next.

Can each process produce at the same rate or do any produce at a faster or slower rate?

A more efficient concept would be to divide the functions of Bldg 5 to each of the other bldgs where the particular inspection function would be pertinent to the process being completed, cutting out a lot of redundant product transport. If the same personnel perform multiple types of inspections, it would seem easier and more efficient to have the appropriate inspection equipment at each production center and move the personnel rather than the products. This would come closer to the modern concept of "in process inspection" and obviate moving any products declared as nonconforming.

 

[duecesevenOS - 2009]

Re: How do we make a Pull system if operations are in different buildings? your comme

I like DuecesevenOS solution, I will have to assess floor space, 100 part numbers and parts 14 feet in dia will require a lot of Kanban space.

What is the current process if you don't mind me asking? When building 3 wants to start machining out a forged part, do they put an order in and then wait on the part to be made, inspected, and transported. I think your going to find that there is a ton of floor space being used for inventory right now. It should be an organization thing.

This will require some ingenuity to solve but every TPS installation does so...

 

[William G]

What is the current process if you don't mind me asking? When building 3 wants to start machining out a forged part, do they put an order in and then wait on the part to be made, inspected, and transported.

You will love this! A production control person who sits in purchasing and is no where near the production buldings, releases the raw material for forging. Whatever forging can get done, is what is made availble to bdlg 3 for machining. If a customer is yelling for his parts. material is released, forging stops it's job and runs that customers order, then bldg 3 stops it jobs and runs it.etc... (results: lots of split orders, hugh aging numbers and a lot of confusion, wip all over the plant not moving anywhere and quality issues)

I can see the frustration in the managments eyes, but I am not fully confident that they are ready to jump in with both feet just yet. I need to show them the potencial by creating 1 working "virtual cell" with pull, and yes that does include outside processes and vendors. This gives me a training area which I can cycle employees through. I have found this method very effective in the past.

As for the inspection. I will be moving all inspectors out to each building, I hate centeralized inspection, it is wasteful on so many levels.

 

[reigelser]

One of the companies I worked for had an assembly line that consumed subassemblies that were done in a different location/town. The parts were big and needed to sit for 24hrs to adjust to the temperature. The inventory was vendor controlled by a webcam. They routinely looked at the storage location and if necessary triggered a shipment. So they always knew what the consumption was without a physical KanBan or containers. The experiences were very positive with that system.

Joachim

 

[William G]

Cameras were my gut instinct when presented with this problem. However, our DOS based network wil not support the bandwith requirements (I am told anyway) So I will have each area push to a kanban location in the next operation to get my pull!

William