We’re making progress!

On April 12, 2017, in Case Study, Problem Solving, by George Loyer

When we started wave three of the Deviation Analysis, we knew that, in each case, Dydramat dust was only found in production rooms 507 and 508.  Next, we discovered it was found during the regular pre-production inspection.  This inspection takes place just before the start of production on the first scheduled production day after the normal cleaning and maintenance days.  During the inspections on 8, 16 and 24 February and on 3 March they found the Dydramat dust more or less evenly distributed all over the floor and on the production equipment.  Although the Dydramat dust was barely visible, a thorough vacuuming produced from a low of 31 grams to a high of 68 grams.  Analysis of each vacuum bag indicated that in each case the dust was virtually pure Dydramat.  Fortunately, no Dydramat dust made its way into the Microcyn production equipment.  If it had, they would have had to shut down production.

We confirmed that since the Dydramat dust was found in rooms 507 and 508 on 8 February, the only time Dydramat dust has been found is during the regular pre-production inspection.  We know that because since 9 February Product Quality has been checking all active Microcyn production rooms on an hourly basis.  They have found no trace of Dydramat dust.  The only time it is found is during the regular pre-production inspection.

Whenever there is a problem like this, lots of Likely Causes start to fly around, mostly from people not directly involved in the Deviation Analysis.  Based upon the information we had at this point in the Deviation Analysis, we could conclusively rule out the following possible causes that were flying around:

  • Incompetent operators are letting Dydramat dust fly around.
  • The sealing equipment in the clean-up room doesn’t work right.
  • The production equipment in question was used in Dydramat production during the previous cycle.

Tip of the day:  When you do a good job of gathering, sorting and organizing information, you can rule out Likely Causes that do not make sense.

Next time we’ll look at the true Likely Cause and how we proved it.

 

 

When we showed up on 8 March, Pharmco had recently completed construction on floor 5.  The construction converted the US FDA Certified Clean Storage Room into the new Production Equipment Cleaning Room.

Although the construction was scheduled to be completed by 29 January, it was not completed until
5 February.  This was due, in a large part, to some modifications to the Heating, Ventilation and Air Conditioning (HVAC) system on floor 5.  The modifications involved the removal of the air lock which was required for the US FDA Certified Clean Storage Room.  The US FDA Certified Clean Storage Room was entered once or twice a month at most.  The Production Equipment Cleaning Room is entered hundreds of times a day.

To go through the air lock people would enter the air lock, close the door behind them and wait for the HVAC system to create a negative pressure in the air lock.  This negative pressure would then release the air lock door to the US FDA Certified Clean Storage Room.  The people could then enter the US FDA Certified Clean Storage Room.  When the people were ready to leave the US FDA Certified Clean Storage Room they would push a button in the Clean Storage Room and wait until the HVAC system created negative pressure in the air lock.  This would release the door allowing them to return to the air lock.

The HVAC experts decided to remove all the air handling equipment from the air lock.  This meant that the entire HVAC system for the new Production Equipment Cleaning Room needed to be reworked.  This extra work delayed the completion of construction by about a week.

Several people blamed that construction on the Dydramat contamination in the Microcyn Production Rooms.  We could eliminate that as a Likely Cause for two reasons.  First, all the Floor 5 Production Rooms were sealed in an FDA approved manner during the entire production process.  Second, the construction was completed by 6 February, yet there was documented contamination on 8 Feb, 16 Feb, 24 Feb and 3 March.  Yes, construction might explain the contamination found on 8 Feb.  But there is no logical way to blame construction for the contamination found on 16 Feb, 24 Feb and 3 March.

Ruling out construction as a Likely Cause opened people’s minds so we started to gather more information.  Next time we’ll start to look at the Deviation Analysis we they did.

 

Last time we found the cause of the SS III right movement swing cylinder hoses pulling out of the fitting at the block end of the hose.  So, what next?  But, first, a little background.

Do you remember the title of the first post in this series?  It was, “These hoses have lousy crimps.”  Before we were called in, this client was sure the problem was bad crimps on the hydraulic hose fittings.  To them, that was the only explanation.  How else could a hydraulic hose pull out of a fitting?  Not to be pointing fingers, but, they came to this conclusion without gathering any information!

After less than an hour of data gathering we could rule out bad crimps.  Refer to our second post in this series for details.  So, the first tip of this series: drawing a conclusion without any data gathering often leads to taking costly, time consuming inappropriate action.

Now to the fix.  Do you think that making the hose specification longer and leaving it at that will truly solve this problem?  Hope you said, “No!”  This incident led Mighty Mountain Manufacturing to take a close look at all their hose specifications.  To their surprise, about 65% of their hose length specifications were not optimal.  So, they fixed them all!  Now the second tip of this series: finding the cause of a Deviation often brings to light an opportunity!

Next time we’ll start to look at another real-life problem upon which we worked.

 

We’re closing in on the solution!

On February 14, 2017, in Deviation Analysis, Problem Solving, by George Loyer

The first Deviation Analysis session, among other things, gave us the following:

  • Something changed on or about 18 July
  • Whatever sponsors this deviation happens in Operations Test
  • There must be something different about the SS III when compared to the SS I & SS II as it is the only one with the failures.

We decided to look at “something changed on or about 18 July’’ first.

We found that on 10 July a shipment of hoses was received from a new supplier.  That lines up quite nicely with the first failed hose.  Mighty Mountain Mining keeps a 6 day + /- safety stock on hand.  They replenish stock in a loose First in First Out (FIFO) stock rotation.  The hoses are restocked from the back of the bin and withdrawn from the front of the bin.

That led us to look at the hose specs.  We found that the hose in question had the following spec: (click image to enlarge)

Further investigation determined that the old supplier was always on the “long” side of the spec and the new supplier is on the “short” side of the spec.  At this point we did not know if hose length was a factor, but, it is something we noted for future reference.

Next, we looked at “whatever sponsors this deviation happens in Operations Test.” We found that in operations test each function is driven to its extreme limit 10 times.  We determined that the failure occurs anywhere from the 2nd to 8th test of the swing cylinder.  We knew this was significant and also noted it for future reference.

Next time we’ll look at “There must be something different about the SS III when compared to the SS I & SS II as it is the only one with the failures.”

 

 

 

We got the answer!

On February 1, 2017, in Deviation Analysis, Problem Solving, by George Loyer

Last time we looked at “something changed on or about 18 July” and “whatever sponsors this deviation happens in Operations Test.”  This time we’ll look at, “there must be something different about the SS III when compared to the SS I & SS II as it is the only one with the failures.”

The team dealing with “there must be something different about the SS III when compared to the SS I & SS II” found that the SS III has a hydraulic block that is different from that of the SS I & SS II.  Click link to see the diagrams troubleshootinglogic.com/?p=5319.

As soon as we saw that the SS III had relocated the position on the hydraulic block of the swing cylinder ports we knew we had something upon which to follow up.  One of the team members pointed out that the specification for hose length had not changed when the ports were relocated.  A quick visual inspection of an SS III made it clear that there was tension on the hose at the block fitting.  When a hose on the lower end of the length specification was installed, there was enough force to pull the hose out of the fitting after a few full swings in Operations Test.

Next time well discuss the “fix”.

 

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Last time I concluded by saying, “Next time I’ll share with you what we found during the Deviation Analysis.”  Because not every member of the problem-solving team had hands-on experience, the first thing we did was to make sure everyone had a good understanding of the SS series backhoes.  See below: (click images to enlarge)

By the end of the first Deviation Analysis session we determined the following:

  • All the failed hoses were SS III swing cylinder right movement hoses
  • Each and every failed hose pulled out of the fitting at the hydraulic block end of the hose.
  • Bursting, leaking, getting cut, which are the most common type of hydraulic hose failures, were not observed.
  • The first failure was on 18 July.
  • There was 1 failure on 18 July.
  • There were 4 failures on 21 July.
  • There were 6 failures on 22 July.
  • There were 9 failures on 23 July.
  • All the failures occurred during the operations test.
  • To date there have been a total of 20 hose failures.

Based upon the above we were able to do the following:

  • We ruled out defective fittings, and / or defective crimping because all the hoses that failed are on the SS III swing cylinder right movement hose.  It is statistically impossible for all 20 of the hoses with defective fittings, and / or defective crimping could have “randomly” been installed on the SS III swing cylinder right movement position on the SS III hydraulic block.
  • Something changed on or about 18 July.
  • Although we cannot prove it statistically, the failure rate appears to be increasing.
  • Whatever sponsors this deviation happens in Operations Test.
  • There must be something different about the SS III when compared to the SS I & SS II as it is the only one with the failures.

In this two and one half hour Deviation Analysis session, we made excellent progress.  Next time I’ll share with you what we did next.

 

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These hoses have lousy crimps!

On December 14, 2016, in Case Study, Deviation Analysis, by George Loyer

Last time I concluded by saying, “Next time I’ll start sharing with you some stories about the companies with which we have worked,” so here goes.  A company I’ll call Mighty Mountain Mining (MMM) is an internationally known manufacturer of medium and heavy construction equipment.  Their specialty is earth-moving equipment.

The smallest earth moving equipment they make is their line of hydraulic backhoes.  They currently offer three backhoe models.  The SuperScoop I (SS-I) and SuperScoop II (SS-II) were introduced simultaneously five years ago.  They have one of the best overall service and durability records in the industry for their class of equipment.

Ten months ago MMM introduced the SuperScoop III (SS-III), a large capacity heavy duty back hoe.  It was designed to fill the gap between backhoes and their larger excavators.  The SS-III has the same basic design as the SS-I and SS-II.  The major differences between the SS-III and the earlier models are:

  • a higher capacity hydraulic system
  • a stronger alloy steel reinforced frame
  • a 30% larger digging bucket

The SS-III had the best initial product record of any piece of equipment that MMM ever produced.  Then a series of SS-III product failures began occurring.  Those SS-III failures were a big concern at headquarters.  The timing could not have been worse!  MMM was about to start a major marketing campaign for the whole SS line of backhoes.

The cause of these failures needed to be found quickly and eliminated.  A Problem-Solving Team was, therefor, formed.  We were called in to lead that team.  When we arrived, we were told that the problem was that hydraulic hoses were pulling completely out of the fitting.  See below:

Next time I’ll share with you what we found during the Deviation Analysis that followed.

 

 

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