Wednesday, October 23, 2013

Focus and Leverage Part 266

Focus and Leverage Part 266

In this posting Bruce presents the system analysis performed by the improvement team.  And like the last posting, Bruce asks you the readers a question at the end of this posting and we welcome all of you to post an answer to it.

The System Analysis – More information and Details

With the tour information in hand, it was time for the improvement team to go back and do a  more detailed system analysis and look for the cause-effect-cause relationships at each work station and determine what the improvement strategy should be.  Let’s go back through each process step (work station) and look for more detailed information and clues as to what might be causing the problem.

Step 1 – The Planning

The “beloved” optimization software was an add-on from management.  Management firmly believed the software could be used to improve efficiency and help them reduce cost per part and save on scrap material.  In isolation the software might have some benefits for a single panel, but when subjected to the number of panels required to complete a single project, the software did pose some drawbacks. The foundational logic of the software was to analyze and calculate optimization for a single panel.  However, the software did not take into account or calculate the effects on a total project.  Overall, the global negative effects of following the software recommendations did cause some problems!

Each project manager usually had several jobs assigned to them to manage.  At any given time the project managers could have three (3) or four (4) jobs at various stages of the planning or production process.  The current rules for the project managers were simple:

1) Keep everyone busy (Efficiency).

2) Release work to the floor as soon as it was ready to go (in hopes of getting it completed on time).

3) Keep pushing the job through the system.

Step 2 – The Lay-up

The lay-up process was pretty straight forward.  The capacity of the lay-up team (2 individuals) far exceeded the needs of the saw.  This work station was able to keep up or exceed the needs of any of the work stations including doors and drawer fronts – plenty of capacity!  The only observed issue for lay-up was sometimes a raw material non-availability.  It could happen that extreme laminate colors had been chosen, which required a special order and could delay arrival.  These kinds of things didn’t happen often, but they could.

Step 3 – The Saw

The saw operator was following the wishes of management by trying to extract the highest levels of efficiency that he could from the saw.  As such, the saw operator was totally focused on maintaining a very high “efficiency” at the saw, because he was measured to make sure the saw was always busy.  The internal mantra seemed to be; “If you don’t cut it, we can’t make it…”  Partially true, but also totally wrong!

Frequently, there were times (daily) the saw operator would “override” the optimization software and change the cutting sequence.  Several years of experience had taught him that the software was not always right and he had developed a better way to do it!

In the saw operators way of thinking, and also managements way of thinking, this was always a great opportunity to save money, if he could manipulate the process and change things to increase efficiency and reduce the cost per part.

In time, the operator had learned that the highest saw efficiency happened when he changed (overrode) the software to cut the panels differently.  Because of his experience the saw operator was able to look at the entire project cut sequence and determine the number of boxes that were all the same size.  As an example, in the case of a school project, it was clear that all of the boxes required, in all of the classrooms  basically the same size – in other words, each classroom was the same - almost.  Many times the boxes would vary in size because of a corner unit, or the length of wall, or some other variable but, he could still get very close in his calculations.  Besides, he would/could do the corner units and other various box sizes at a later time.  Right now efficiency was the most important measure.

When cutting pieces for the box, the left side and the right side are exactly the same. This could vary based on box height requirements, but even then, they were all the same. The tops and bottoms could be a different size depending on the width required and the sequence location (i.e., corner unit), but, for the most part the tops and bottoms were the same. 

The saw operator reasoned that if he went through the entire job and cut ALL the left and right sides before cutting the tops and bottoms, he would be able maximize the efficiency of the saw by reducing the number of times he had to change the setup and give new instructions to make a new cut.  By every measure of efficiency the saw operator was running at maximum efficiency.  The saw operator was very proud of himself for what he could accomplish and management was also proud of him!  He was highly efficient and saving the company a lot of money – or, so they thought.

Step 4 – Edge Banding

There were two operators at the Edge Banding machine.  One operator would feed the part into the machine and the other operator would take it out at the other end and send it back for additional edging or put it on the pallet for transfer to the next work station if it was finished edging.

For the Edge Banding operators it really didn’t make much difference which part they had - the process for edge banding was the same.  The only thing that really made a difference to them was the color of the edging or if it required wood banding.  The banding materials came in big rolls which made changing from one color to another very easy. Change-out was about two (2) minutes, or less.

Step 5 – The Morbidelli

The Morbidelli was operated by a single operator.  The Morbidelli work deck was actually about 40 inches off of the floor.  The set-up of the work deck allowed for two panels to be drilled at a time, sometimes more depending on the size.

The operator could drill either the flat sides (for the pins to hold the shelves) or drill the side edges for the dowel pegs.  The flat side took a bit more time because there were more holes.  The edges took less time because there were only two or three holes for the dowel pegs depending on the size of the piece.

It is interesting to note that the cutting sequence from the saw actually helped the Morbidelli achieve a higher efficiency.  The operator could set-up to do all of the flat sides first and then set-up to do all the edge holes when the tops and bottoms arrived.  So, in essence, by following the same cut sequence from the saw the Morbidelli work station also appeared to be highly efficient.

Step 6 – The Box Press

It was at the box press that the beloved “efficiency” model fell apart!  There was, at any given time, several pallets of inventory waiting in the holding area for the box press.  In some cases there were pallets stacked on top of pallets (with the help of a forklift), just to better utilize the space available.

There were two Box Press operators and they were stuck!  Considering all of the work in process (WIP) waiting in front of their work station, they DID NOT have enough of the right parts to build a single box!  What they usually had was ALL left sides and the right sides and the backs but, no tops or bottoms.  It wasn’t until the first tops and bottoms had completed the other processes and started to arrive at the box press that they could start assembly.

When the tops and bottoms did start to arrive, it was sometimes very difficult to match the pieces for the build.  The reason was, the width of the boxes had a much higher probability of changing then the height did.  At times, it was like putting all the pieces of a puzzle on a table and trying to figure out which pieces went where.  Even though most of the boxes were essentially the same size, it usually turned into a “hunt” to find the right pieces for assembly.  This problem existed because each piece was marked with job number and cabinet number.  Even though each piece was EXACTLY the same, the operators would spend considerable time trying to match the job numbers and cabinet numbers!

This matching of the necessary parts also played heavily into the slow production time of the box press.  The reality was the box press operators spent most of their time “looking” for, and not “pressing” parts.  By all measures the box press operators were very busy, but they just weren’t accomplishing the job of pressing boxes.

Step 7 – Final Assembly

The assembly crews in final assembly seemed to have the most down time.  I say crews because there was one crew who did the drawers and another crew who did the doors.  Sometimes the hardware could be mounted early for drawers and doors.  When the doors arrived they could have the hinges mounted on them prior to the boxes showing up.  However, taking this early action, to mount hinges on the doors, also generated a large amount of re-work.  The correct assembly process was to first mount the hinge to the box and then the door to the hinge.  This allowed them to do the proper alignment when the door was attached.

The door crew often assembled out of sequence just so they would appear to be busy.  They took this action knowing full-well they would eventually have to re-work it.  But, it did meet the measure of being busy and efficient “right now”!

Step 8 – Shipping

When the boxes arrived at shipping they were individually wrapped in plastic.  They had several different plastic rolls on applicators that they could use and there were, at most times, probably 3 or 4 folks in shipping area.  They had the capacity to keep up with the boxes coming from Final Assembly.

When the boxes were wrapped, the box number was checked-off of the project list and either loaded directly to the truck or placed in a holding area waiting for the truck to return.  The primary measure of shipping was to make sure the truck was fully loaded in order to maximize the load going to the job site and reduce the number of times the truck had to make a trip, reducing the fuel costs and saving money, and therefore being more efficient!  A truck was rarely allowed to leave for a job site only partially loaded, unless it was to take the last pieces required to hopefully finish the job.

As an added note, there were complaints from the installers at the job sites.  Even though lots of boxes were showing up at the job site(s) it consisted of only a few boxes in each room.  The installers had some pieces of the puzzle, but not enough of the right pieces to finish the installation.

The System Analysis

With the collection and observation of this additional information, the system started to reveal itself and subsequently take on a life of its own.  For the improvement team the necessary actions started to take shape for what actions were necessary to transform the situation.

By now, many of you might have concluded where you think the constraint is.  Based on what you have read (and your mental list of improvements) you’ve probably deduced which work station is slowing down the entire system. What do you think the constraint of this system is?  Where would you focus your improvement efforts?  Why would you pick that particular location or operation?

At first blush, many people might point their finger at the Box Press.  By using traditional system analysis techniques and protocol, i.e., looking for the slowest operation, looking for the point where the work seems to be backed up and the point that exhibits the highest level of work–in-process inventory, the box press would certainly be a plausible candidate.  But, is it really the problem area?  If the Box Press was able to produce at a faster rate, would the entire system get better?  Maybe!  Remember:  The Box Press has its own set of limitations.  Each box is required to stay in the press for at least 3 minutes to set the glue!  Can the Box Press go any faster than it already does with these limitations?  How?
Bob Sproull


Anonymous said...

I see couple of problems. BoxPress crew is "looking" instead of pressing and assembly crew is waiting (and so the installers). Different box pieces are coming (flowing) in "wrong" order after a saw & drill. And that is due the "efficiency" at the saw. Maybe the "installing order" would be better manufacturing order.

Anonymous said...

The main issue is with the "optimized" initial cutting at the saw. By trying to optimize the cuts for an entire job, they are essentially turning that operation into a batch operation. The next couple of steps appear to be okay, and even more efficient, because they work on individual pieces. The problem shows up at the Box Press because they are trying to match components together and they are unable to put a box in the press until they get both the sides and the tops and bottoms (remember, the saw operator was cutting all the sides for the entire projct first and then the tops and bottoms). In an operation that there is a fixed amount of time required, it sounds like they are spending more time trying to match the right parts together for a box than the box is spending in the press.

If the saw step would switch to cutting all the pieces for a box together, instead of all the sides for the project then all the tops and bottoms, those components could flow through the rest of the steps together. Once these hit the Box Press step, the crew would have all the components together, thus eliminating the wasted time of looking for the right components. In addition, they would be able to put the boxes in the press as they came off the Morbidelli and not have to wait for additional components to show up. This would move them to a "one box flow" that should help alleviate the constraint at the Box Press.

I would start with the above change and see what falls out from it before making any other recommendations.

Bob Sproull said...

To Anonymous 1: Each and everyone of your observations is correct! But with so many different things going on if, you had to prioritize them which might be first? Is there one issues that might be more important than the other? In others words, if you focused on one could you also receive benefit for some others - perhaps even by default!!

Your system observations are very keen and I applaud your ability to sort through the mess and focus on the items that you did. Excellent job!

Bruce Nelson

Bob Sproull said...

To Anonymous #2: Your visualization of the production floor, and the mess it was in, is very perceptive. You've informally described the "system" problem(s) when efficiency is viewed in isolation from the entire system. It presents a situation where, essentially, everyone was working against everyone else. The system was being managed, and measured, in terms of individual efficiency and not a team effort.

You immediately saw, and described, the issues that efficiency creates for batching. Excellent observations on your part. You have a keen eye for systems analysis!

Bruce Nelson