Implementing a Pull System in a manufacturing line? Lessons Learned?

[johnnybegood]

How to go about implementing Pull System in a manufacturing line?
I would appreciate some lesson learn....the difficulty faced and the solution to them.

[WALLACE]

johnnybegood,
What's your definition of a pull system?
Wallace

[johnnybegood]

A system of cascading production and delivery instructions from downstream to upstream activities in which the upstream supplier until the downstream customer signals a need

[Wes Bucey]

In essence, this "pull" system is merely a variation of JIT (just in time.) the slight difference is that the downstream customer has a variable requirement and thus the lead times he expects (wants) are very short.

Incidentally, I am following your usage of customers being "downstream" - many commentators consider the ultimate buyer the "Top" of the supply chain and suppliers at the bottom.

The "Big Lie" in JIT and "Pull" systems is that the various links in the supply chain can reduce their inventories and still be completely responsive to the downstream customers (regardless of how many links down the chain the "trigger" is.)

Ultimately, simply because of physical production times required, one or more links in the supply chain are forced to carry inventory of finished goods or work in process which requires only minor finishing prior to delivery (a new paint job to match color requirement, for example.)

So, as one of the links in the supply chain, you have to map out the timelines of obtaining materials from the links (suppliers) above you so you can supply ANY of the configurations or quantities your downstream customers may request. As time progresses and you learn more about these customers, you will be able to predict a minimum/maximum requirement for each downstream customer and gage your raw material and finished goods inventories accordingly so you can be "instantly" responsive to a "pull" command from a downstream customer.

This is NOT easy. Really top-notch analysts who do this kind of prediction earn well over $100,000 up to $250,000 per year. It requires intimate knowledge of ALL the links in the supply chain and their capabilities and capacities, which is constantly monitored.

Example: ABC company (your supplier) may be capable and have capacity to produce 100,000 units/month. If you need 25,000 units next month, you may be out of luck if ABC is committed to delivering 95,000 units per month to other customers for the next six months. The top notch analyst keeps his finger on the pulse of things like that. It requires intense rapport and communication with every link in the supply chain to work with the most efficient use of assets and avoid "muda" (waste.)

In light of this brief discourse, do you have some more questions or details to offer?

[WALLACE]

Originally Posted by johnnybegood

A system of cascading production and delivery instructions from downstream to upstream activities in which the upstream supplier until the downstream customer signals a need

Thanks johnybegood,
I noted that your request was for lessons learned re- implementing a pull system in a manufacturing line.
Would you please let us know what you are producing, how many lines you have and how many internal production departments support your production.
Another piece of info required: do you currently have control points (Repair/Rework stations) in operation, or are you practicing "In station quality control"?
Wallace.

[Jim Howe]

Originally Posted by johnnybegood

How to go about implementing Pull System in a manufacturing line?
I would appreciate some lesson learn....the difficulty faced and the solution to them.

From the limited education I have received in the past two months on Lean. The pull system represents the ultimate goal of manufacturing. During our 101 simulation training we found it much easier to maintain tact time if each stage of the process kept one piece in inventory. We found this completely eliminated delay time. The one piece acted as our kanban signal to produce another piece.
Secondly we learned that a full pull system is extremely difficult to implement and maintain with out going through all the necessary steps to get there. In other words do not jump directly to pull. let that be your ultimate goal. meanwhile proceed with your lean tools to flatline your processes. you may even go through several push-pull systems on the way.
Hope this helps

[wmarhel]

Originally Posted by johnnybegood

How to go about implementing Pull System in a manufacturing line?
I would appreciate some lesson learn....the difficulty faced and the solution to them.

A decent read on this is "The Goal", by Goldratt. Not a "how-to" book by any means, but a good enough read to help people think differently than they might currently be doing, and simple enough for the reader to not feel overwhelmed. It is pretty amazing how many people out there don't pick up a book once they are done with College or a specific course of study.

[wmarhel]

Originally Posted by Wes Bucey

In essence, this "pull" system is merely a variation of JIT (just in time.) the slight difference is that the downstream customer has a variable requirement and thus the lead times he expects (wants) are very short.

I would like to add one thing to this...."pull" is more of a sub-component of JIT, not really what I would I call a variation. The two are pretty much synonymous it just depends on what “buzz” word the consulting world is pitching at the time. Toyota referred to it as JIT with a mechanism of achieving it being “pull”.

Originally Posted by Wes Bucey

Ultimately, simply because of physical production times required, one or more links in the supply chain are forced to carry inventory of finished goods or work in process which requires only minor finishing prior to delivery (a new paint job to match color requirement, for example.)

Yes, but those levels of inventory should be looked at as additional opportunities for improvement. Other methods such as reduction in set-up times, improvement in quality yields, and a host of other things should be addressed as well in order to ensure the lowest levels of inventory. Just because things are working smoothly doesn’t mean they shouldn’t be fixed.

Another key component should be to maintain materials in its most flexible condition. Simply put, if material “111” can be manufactured into parts: “A”, “B”, and “C” with parts each receiving the following operations:

“A” – Steps 1, 2, 3, 4
“B” – Steps 1, 2, 4
“C” – Steps 1, 2, 5

It makes the most sense to maintain inventory of material “111” that has had Steps 1 and 2 performed versus maintaining an inventory level of “A”, “B”, and “C” separately. Of course this depends on individuals process, product and business.

Originally Posted by Wes Bucey

This is NOT easy. Really top-notch analysts who do this kind of prediction earn well over $100,000 up to $250,000 per year. It requires intimate knowledge of ALL the links in the supply chain and their capabilities and capacities, which is constantly monitored.

Where do I find one of those jobs.

I’m fighting this battle as I type this, driving a conversion from a traditional system to a “pull” method. I’m essentially combining five non-adjacent buildings with three different business units into two adjacent facilities. Since we are seasonal, we will be maintaining levels of finished goods throughout the year, along with restructuring where the WIP levels build-up and at what level.

Capacity should also be designed into the manufacturing process. For instance, I’m taking two lines (they both run the same product) of three people each (no extra space for additional people on the line) and creating one line capable of supporting seven stations/people and cutting the materials sitting at the line in half. It doesn’t matter whether I run the line with the seven people or only three if the need occurs. I'll also be looking at about a 25-30% reduction in non-value added labor content.

The key fight isn’t with the production associates (in this case union), but with supervisors and middle managers who feel your taking away their power and hence, destroying the little empire they have built-up over the years.

Wayne