The link below is an article about the value of certification for manufacturers. It is a heavy sell for certification. In my opinion it misses the most basic benefit of certification, which is the path to getting certified.
When people ask me about ISO 9000, the simple explanation I give, “the process of certification requires you to write down your process and demonstrate that you follow the process.” The certification system does not dictate your process.
The mere action of writing down and maintaining the written procedure is the real value. In one of my blogs “Dumbest Guy in the Room", written in two parts, http://www.jagengrg.com/blog, I touch on the value of the written word and the perils of oral communication.
Writing it down allows everyone to see exactly what the author thinks is being done or should be done. Others can read the written word and identify ambiguous sections, missing information, or errors that can easily be overlooked using oral communication.
When everyone is carrying the information in their head’s via oral direction I can guarantee there is more than one interpretation. I would venture to say you will have as many interpretations as you have people involved.
When written procedures do exist but do not come under the scrutiny of a certification body, it is very common for procedures to become stale, be incomplete, rely on undocumented knowledge, and for steps in the process to be missed from time to time.
The subject article closes with a realistic assessment of the value for certification. “Is having a certification the end-all-be-all of manufacturing? No. However….”
You reach the "however" stage, not my hanging the certification on the wall, but the process for obtaining it.
This came to me via e-mail. I am sure little of this is 100% correct. But just think if just 50% are 50% correct.
The Exponential Age?
Just a few things for us all to ponder, especially the younger ones amongst us.
Did you think back in 1998 that 3 years later you would never take pictures on film again?
In 1998 Kodak had 170,000 employees and sold 85 % photo paper worldwide. Within just a few years their business model disappeared and they went bankrupt. What happened to Kodak will happen in a lot of industries in the next 10 years and, most people won't see it coming.
Yet digital cameras were invented in 1975. The first ones only had 10,000 pixels, but followed Moore's law. So as with all exponential technologies, it was a disappointment for a time, before it became way superior and became mainstream in only a few short years. It will now happen again with Artificial Intelligence, health, autonomous and electric cars, education, 3D printing, agriculture and jobs. Welcome to the 4th Industrial Revolution. Welcome to the Exponential Age.
Software will disrupt most traditional industries in the next 5-10 years.
Uber is just a software tool, they don't own any cars, and are now the biggest taxi company in the world.
Airbnb is now the biggest hotel company in the world, although they don't own any properties.
Artificial Intelligence: Computers become exponentially better in understanding the world. This year, a computer beat the best Go-player in the world, 10 years earlier than expected.
In the US , young lawyers already don't get jobs. Because of IBM's Watson you can get legal advice (so far for more or less basic stuff) within seconds. With 90% accuracy compared with 70% accuracy when done by humans.
So if you study law, stop immediately. There will be 90 % less lawyers in the future. Only specialists will remain.
Watson already helps nurses diagnosing cancer, which is 4 times more accurate than human nurses.
Facebook now has a pattern recognition software that can recognize faces better than humans. In 2030 computers will become more intelligent than humans. (NEVER says Albert)
Autonomous cars: In 2018 the first self driving cars will appear for the public. Around 2020 the complete industry will start to be disrupted. You won't want to own a car anymore. You will call a car with your phone, it will show up at your location and drive you to your destination. You will not need to park it, you only pay for the driven distance and can be productive while being driven.
Our kids will never need to get a driver's licence and will never own a car.
It will change the cities, because we will need 90-95% less cars for that. We can transform former parking spaces into parks.
1.2 million people die each year in car accidents worldwide. We now have one accident every 60,000 miles ( 100,000 km), with autonomous driving that will drop to 1 accident in 6 million miles (10 million km). That will save a million lives each year.
Most car companies will probably become bankrupt. Traditional car companies try the evolutionary approach and just build a better car, while tech companies like Tesla, Apple, Google will do the revolutionary approach and build a computer on wheels.
Many engineers from Volkswagen and Audi are completely terrified of Tesla.
Insurance companies will have massive trouble because without accidents, the insurance will become 100x cheaper. Their car insurance business model will disappear.
Real Estate will change. Because if you can work while you commute, people will move further away to live in a more beautiful neighbourhood.
Electric cars will become mainstream about 2020. Cities will be less noisy because all new cars will run on electricity.
Electricity will become incredibly cheap and clean. Solar production has been on an exponential curve for 30 years, but you can now see the burgeoning impact.
Last year, more solar energy was installed worldwide than fossil. Energy companies are desperately trying to limit access to the grid to prevent competition from home solar installations, but that can't last. Technology will take care of that strategy.
With cheap electricity comes cheap and abundant water. Desalination of salt water now only needs 2k Wh per cubic meter at 0.25 cents). We don't have scarce water in most places, we only have scarce drinking water. Imagine what will be possible if anyone can have as much clean water as he wants, for nearly no cost.
Health: The Tricorder X price will be announced this year. There are companies who will build a medical device (called the " Tricorder " from Star Trek) that works with your phone, which takes your retina scan, your blood sample and you simply breath into it.
It then analyses 54 bio-markers that will identify nearly any disease. It will be cheap, so in a few years everyone on this planet will have access to world class medical analysis, nearly for free. Goodbye medical establishments.
3 D printing: The price of the cheapest 3D printer came down from $18,000 to $400 within 10 years. In the same time, it became 100 times faster. All major shoe companies have already started 3D printing shoes.
Some spare airplane parts are already 3D printed in remote airports. The space station now has a printer that eliminates the need for the large amount of spare parts they used to have in the past.
At the end of this year, new smartphones will have 3D scanning possibilities. You can then 3D scan your feet and print your perfect shoe at home.
In China they have already 3D printed and built a complete 6 storey office building. By 2027 10% of everything that's being produced will be 3D printed.
Business Opportunities: If you think of a niche you want to go in, first ask yourself, "In the future, do I think we will have that?" If the answer is yes, how can you make that happen sooner? If it doesn't work with your phone, forget the idea. And any idea designed for success in the 20th century is doomed to failure in the 21st century.
Work: 70-80 % of jobs will disappear in the next 20 years. There will be a lot of new jobs, but it is not clear if there will be enough new jobs in such a short time. This will require a rethink on wealth distribution.
Agriculture: There will be a $100 agricultural robot in the future. Farmers in 3rd world countries can then become managers of their field instead of working all day on their fields.
Aeroponics: Will need much less water. The first Petri dish produced veal, is now available and will be cheaper than cow produced veal in 2018. Right now, 30 % of all agricultural surfaces is used for cows. Imagine if we don't need that space anymore.
The Times They Are A Changing!
Recently I was interviewed by a Mechanical Engineering student on the importance of communications. I’m approaching 40 years in engineering practice so the examples began to flow and the student’s 15 minute time estimate for the meeting quickly turned into two hours. The meeting itself was a lesson in communications. My awareness of the root cause, that I will describe below, I believe made the information more valuable.
The student and I covered many issues on the topic of communications, but the emphasis of his questioning was the difference between communicating with other engineers versus business majors or the sales personnel. The root issue of communications I believe goes deeper and must be identified to minimize the occurrence.
There have been many occurrences of communication problems in my life and not all involved engineering. In the past, I viewed each incident as individual and isolated events. Of late, I have come to the conclusion there are common causes. Here I address one that I think is more common than realized.
Communication problems are often dismissed as the language, generational, or cultural gaps. These all contribute to the issue but are not the root cause of a large portion of communication problems. If fact, obvious language issues often result in precautions being taken to avoid miscommunications.
About 25 years ago I was among a group of technical people gathered for a seminar. While waiting for the speaker, conversations started within the group. Two people were carrying on an energetic conversation for 10-15 minutes consisting of acronyms -- just alphabet soup. Just prior to the speaker arriving, the two having the conversation realized each used a particular acronym for entirely different and unrelated meanings. Yet these two had conversed as if they were on the same subject. Imagine if the conversation had developed into a disagreement to the point of anger, and the instructor arrived before these two were able to define terms. Both would have left thinking badly of the other and maybe worse.
In another situation I was just hired into a new position by a former coworker, now manager of a program. He asked that I do something which I immediately did. At our next meeting, the manger began to tell me how I should go about doing the task. I was fuming, to say the least. I was saying to myself, "what was wrong with the way I did it?" I fumed and fumed until I finally asked. The manager looked at me in astonishment and said “You did it? I am not use to anything getting done so fast around here.”
One final example. A new VP of engineering admonished me for my poor design and release process causing many problems – no specifics were provided. I was shocked to the point of speechlessness, so I did not immediately ask for specifics that would have revealed the root cause of his dissatisfaction.
I assumed my 2 + year old procedure had grown stale and caused problems. I printed a copy of my Design and Release Procedure and read it line for line, looking for something that was no longer correct. After failing to find any problems, I wrote in large red letters “Tell me what I need to change.” The boss was not at his desk, so I left it on his seat. Sometime later, a much more humble boss came to my office and asked if the release date on the procedure was correct – it was, and about 2 years old, so I said yes, and he left.
All three examples have the same root cause. In each case one or both parties assumed implicitly that the other party knew something that in reality they did not.
Case One: Each party assumed that a particular acronym meant the same to each of them.
Case Two: I implicitly assumed the manger would know that I would quickly act on the simple assignment. We had worked together for 6 years prior, on a different program.
Case Three: The VP had come to believe implicitly that there was no written process. In his mind, every problem that arose appeared to be a result of not having a process. I assumed he was talking directly to the written document that he did not know existed.
As an independent Professional Engineer many of my clients are not engineers. What were once safe assumptions while working in an engineering office with other engineers, I learned quickly was no longer acceptable.
Current technologies allow people from around the world to communicate with incredible ease. This has resulted in the root-cause I suggested above to run unchecked. When we write we need to be aware of generational, language, or cultural gaps as well as office jargon*. All can easily result in implicit assumptions of other people’s knowledge that are false.
The first professional letter I wrote to be send outside the corporation was brought back to me by my supervisor. He called to my attention that office jargon has no place for a formal business letter. Here again, I was implicitly assuming the terms used every day in our group would be universally understood. It took me 40 years to “connect the dots.”**
* Special words or expressions that are used by a particular profession or group and are difficult for others to understand.
** To understand the relationship between different ideas or experiences
I get great satisfaction when working with my hands. When I do so I always ask why the item I am working on is as it is. One source of frustration I believe many have experienced it the lack of tool access. Sometimes n-1 fasteners are a breeze to access and the nth takes more time to remove than all the other combined.
I don’t recall from my machine design class ever addressing this real world situation. I learned how to size bolts, bearings, and cross-sections but I don’t recall any mention of tool access. I learned there existed standards for tool access when I entered industry. In the auto industry one thing you tried to avoid was the need for special tool kits. These were not cheap and every automobile dealer and repair shop needs to purchase the special kits if they intend to make the particular repair. As much as this was avoided 30 years ago (and I assume still today) these special kits existed.
While working in a different industry we were cleaning up a lab area. I came across an Allen Wrench (hex key) that did not make the usual 90 degree bend. It brought to mind the special kits I mentioned above. It had been modified to have a second bend nearly 90 degrees. I taped it to the wall in the design department with the following note. Do Not Design Anything That Needs a Tool Like This!
There are reasons a lack of tool access happens. Parts designed for one application may have been created with adequate access. The same item is later used on a different application and the surrounding space is already accounted for. But there are cases where there simply is not enough thought applied or too many bean counters controlling the design function.
As the Wyoming winter approaches there are things that need attention. Today two of those frustrations had to be addressed.
I have a generator for times when power goes out and an ATV (all terrain vehicles) for snow removal. Both have batteries for starting. Battery removal is more difficult than it should be for both.The generator can be manually started but if needed when it is -20F (-29C) that can be quite an effort.
For the ATV the battery is held in place with two screws and a padded flat metal bar across the width of the battery. This is an (n-1) example. One of the two screws has plenty of access and the other is under a plastic housing. What would make it more user friendly (for those who buy the products) would be to make the end of the retaining bar that is under the plastic housing, slip into a slot of some kind. The other end which is very accessible would use the one screw. This would eliminate one fastener, eliminate the captured nut or tapped hole (can’t see what is there) and make battery removal so much easier for little or no cost.
My solution which could easily be incorporated at the factory was to cut a slot on the end of the bar with poor tool access. Doing so eliminated the need to remove the hidden fastener. Just loosen enough to slip the retaining bar out then back in. You can rotate the retainer but it must pass over the positive terminal and the bar is grounded to the frame. Better to remove it.
For the generator I speculate this is the multi application issue. The same design is sold with and without battery start. These options don’t come cheap and if as in the auto industry, have a handsome margin. So why punish the big spenders?
The panel with all the outlets is welded to the frame. The panel extends quite a distance down to provide a billboard for the power rating. Behind the immovable plate lies the battery. Accessing the battery retainers and cables would be simple if the lower portion of the plate was either detachable or eliminated. Since I don’t transport the generator I leave the retainers off. Access to the cables is still more difficult than it need be.
So for those who have not yet entered industry let these two examples provide food for thought when you are designing equipment. Many small improvements can be incorporated for little or no cost prior to production release of the design.
Those about to enter industry seek out the senior engineers and ask for the standards books. Spend some time, even your own time, skimming through the manuals. They contain thousands of man-years of experience. Also spend time in the manufacturing and service facilities if possible. These efforts will provide an insight to what is not taught in class.
Photo 1 Is a top down view of the battery retainer.
Photo 2 You can see the hidden fastener and the modification to the retainer.
Photo 3 Is the generator. The bottom half of the battery can be seen.
Photo 4 Is the side view of the battery.
Photo 5 Shows the bottom half of the battery more clearly than photo 3.
I recall many years ago first hearing the term Over Engineered. It rang a sour note but I had not given it much thought. I still hear this said today about older equipment. For instance the DC Generators at Pratt Institute in Brooklyn NY have been in operation for over 100 years. http://inspectapedia.com/heat/Steam_Systems_Pratt_Milster.php I had the opportunity a few years ago to visit my alma mater. To my surprise and delight the Chief Engineer who provided the tour of the facility to my class in about 1977 was still on the job as was the equipment. But I digress.
Over Engineered is often brought up when speaking about 1950’s vintage American automobiles. “They don’t build them like that anymore”. They don’t build them like that anymore because they don’t design like they use to.
When I worked in the auto industry in the late 70’s and early 80’s engineering was in good part “seat of the pants” designing. A lot less analysis than one would expect. Two-D CAD was just getting introduced. There was extensive testing before production. What a lack of analysis left unknown, testing –often brutal testing- would reveal.
If a component broke it was made stronger by adding more material or eliminating tight radii or other stress concentration features. Whether the rest of the system was just good enough or 10 times stronger than needed was an unknown. Over time components that never failed were targets for cost reduction. This also was not as analytical as it is likely today.
Getting back to the subject of this blog, I would offer that the "weaker" a device is, the more it was engineered. Weaker, because it is designed closer to the expected loads. This of course is aside from shoddy design work. For greater strength the addition of material will usually achieve this. For an item like the generators at Pratt added weight can also help with vibration. The penalties are the onetime cost of added material and greater shipment weight. Adding more material globally to a system such as a rocket, aircraft and to today’s automobile is forbidden. This requires much move engineering.
I hope I have provided a better understanding of the term Over Engineered and realize it is really a misleading expression. Equipment back then was Over Designed because the factors of ignorance were much greater just a few decades ago.
I did not write the linked article. I should have since you will not learn this in school. When we finish 4 or more years of an ME education we are all wound up. We have been working at a pace which would kill us if tried it indefinitely. What shocked me when I entered industry was the trivia that engineers must be involved with. Perhaps like a soldier, you train to fight, but you don't do it 8-12/hr per day for 30 years. I don't know if the following article is accurate for small companies but it is for large corporations. I recall being bored and asked my supervisor for more work. He looked at me for a second or two then asked if I could make him a copy of some document. I said to him if this is what I get when I ask for more work I will eventually stop asking. My suggestion to young engineers is to keep in mind what one of my ME professors told us. “The best thing you can do is to get a job that keeps you as busy as I did.” I don't know if that is possible but I would keep that in mind. The article suggests too much complacency in my opinion. I think you need to know what is coming but don’t settle for making copies.
Since a lot of young people visit this forum I thought it could be of value repeat what I learned 40 years ago.
I did learn the following from one of my professors not in the classroom but during a meeting with her as my adviser. I did not fully appreciate what she suggested though I did follow her advice and it was the correct thing for me.
I was in a city community college (CC). The four year city colleges were somewhat prestigious. The CC prepared students to transfer within the city university system and planned the curriculum to match the methods at the four year city colleges.
I had the option to take mechanics (statics and dynamics) at the CC or wait until I went to a 4 year college. At that time I thought a class was class was a class.
My advisor suggested that I take statics and dynamics at the CC if I were to go to the 4 year city college. That would better prepare me for the more theoretical approach I will find at the city college. If I planned to attend a particular private college, which the adviser had attended and taught, that I was better to take statics and dynamics at the private school. Here the subject matter was taught on a more applied and practical bases.
I now appreciate how subject matter can be presented in different ways. This is important because not all people can absorb material the same way. If you are still in the planning mode for college or an advanced degree do some research about how the material is presented.
A coworker several years ago commented about his master’s degree from a famous college in the San Francisco Bay Area. He said "regardless of the tile of the class, the professors turned it into a math class. Only one class was of any practical value to me."
Over the years I have witnessed a particular mistake repeated. It is usually with an old product that has a problem, or the old product requiring a change or a feature added. The mistake manifests itself with everyone believing they carry the true operation and understanding in their heads. Aside from Scotty aboard the USS Enterprise, most should assume there is something they may not know.
When a new product is being developed the team usually follows some development process with defined tools. Oversight is likely in place with design reviews and gatekeepers of some kind. But humans grow complacent and subconsciously assume these systems must be as they believe it to be. After all we have been making it or using it for years.
If you get involved with Value Stream Mapping you will come to realize everyone has their own reality of how things work. This could almost be a money making parlor tick. Do a demonstration of some process with 15-20 steps to an audience of 20 people. If two in the audience come up with the same detailed step by step process after watching the demonstration, I would be surprised. Usually 2 or 3 people are asked and I have never witnessed two agreeing or any of them being correct on the first pass. The tasking of writing it down will indentify to others what was missed. With repeated passes a complete process can be documented.
Having been a manager of experts in a variety of specialties I have often been the dumbest guy in the room. I know what I don’t know and I am less likely to develop a mental understanding good enough to convince myself I understand.
One example in particular comes to mind. I sat in a meeting to develop a system consisting of electronic devices. This was an add-on or a fix – not new product development where checks and balances are in place. I can’t recall the specifics but the experts were discussing this with great confidence. I was lost and asked that the oral conversation to be turned into a block diagram on the white board.
Just as with Value Stream Mapping the first attempt at the block diagram received corrections from people who a few minutes ago were in oral agreement. I believe it took seven iterations of the block diagram before all the experts agreed.
This is not an attempt to discredit experts. Without them the job would not get done. This illustrates that experts, except Scotty of course, can easily get over confident. When a team is involved it is seldom the case that everyone knows everything. Add the element of time for aged products/systems and it is almost a certainty.
If you are part of a meeting where everyone is in oral agreement it would be prudent to ask for a flow chart or block diagram. The dumbest guy in the room may save the day.
Nearly Forty years ago, a fellow engineer told me a story that must now be 70 years old. This engineer was born and educated in Egypt. His first job was a large civil engineering project with massive amounts of earth moving. Having a formal education but no local real world experience, he started to estimate how many steam shovels and trucks were required for the job. A Sr. engineer asked, what he planned do with all the equipment once the project was done, and what about the 99 local laborers left idle for each machine that does the work of 100 men and requiring only one operator?
The Sr. engineer told the young engineer to base his calculations on the required number of donkeys, basket weavers, strong men, little boys, and laborers that would be required. I was puzzled as was my colleague that many years ago.
The Sr. engineer explained that picks and shovels would be the main tools and the local laborers the muscle. The laborers loosen the soil and then fill the woven baskets with the soil. The strong men would lift the baskets onto the donkeys. The young boys would ride the animal off site and dump the soil. This kept the local population employed and able to feed their families. Manual labor as it was may not have been a great way to make a living but it was far better than starvation.
The situation in ancient Rome was similar. The Romans build magnificent structures but the preferred method was brute force. There was no push for efficiency as we think of it today. Even then, there were labor issues. Better to keep everyone working and fed, if only at subsistence levels, than to have massive unemployment and the making of a revolt.
If the laborers were in a position to demand higher and higher wages mechanization may have advanced faster. It will be interesting to see how many jobs robots and computers will replace as the minimum wage increases to $15/hour regardless of the local economies.
An article appeared in an engineering forum entitled Why Designs Fail. As I thought about the article and the examples presented, the Titanic, Tacoma Bridge, etc., I realized mitigating the consequences of a failure are more important than preventing the failure.
One of the subjects I did not learn in the classroom was Failure Mode and Effect Analysis (FMEA). I do not intend to cover the subject of FMEA but would like to emphasize one small portion. FMEA was introduced to me on my first job in the late 70's. One aspect of human nature needs to be over come when applying FMEA. Problems we do not expect to happen due to low probability, we tend to dismiss with no contingency if it occurs. FMEA forces you to separate probability from consequences.
During my FMEA training I was told to ask what happens if a particular failure were to occur, without arguing over the probability, which is addressed separately. Most homes have smoke detectors and many have fire extinguishers. These items provide early warning and a method to stop or at least slow the progression of a fire until help arrives. Few homes have precautions for an asteroid strike though the results will be far worst with little mitigation possible.
A different state of mind comes into play when you accept the sinking of a ship as a possibility. Expecting to foresee all the possible ways it could happen may be impossible. How a ship could fill with water is irrelevant once it happens.
If the Titanic designers had asked themselves what would happen if the entire ship flooded, not worrying about the how, lives would have been saved. Perhaps the compartments would have been 100% isolated from each other or more lifeboats provided.
A warning by Dr. D. posted on this site reminded me of two funny incidents. Dr. D. was responding to the use of PPM for perpetual motion machine. These initials according to Dr. D. are used for Permanent Magnet Motor. This may sound trivial, but the following, I was not warned about in school.
If you have ever worked in big corporations especially defense or government related there are new languages you will need to learn. Shortly after joining a defense company, I told my boss if I did not get a company-to-English, English-to-company dictionary I was not going to get anything done. He handed me an 8-1/2 x 11” book about ½” thick, printed on both sides, each sheet having two columns. This was a list of Abbreviations, Acronyms, and Initialisms (A, A, & I). Many had multiple meanings.
As a new person, I would ask what a particular A, A, or I stood for. Many company veterans could not tell me. They knew the ABC form was used for a particular task, and the XYZ department did some particular function, but as far as what the A, B, C, X, Y, or Z stood for and they could not tell me. This created my need for a dictionary.
A few years later at a NASA facility, I attended a seminar. Staff from all different departments and unrelated programs attended. Several of us arrived early and self-introductions led to conversations about each other’s work. The instructor was late so the conversations continued for perhaps 20 minutes. Two individuals in particular were having an intense conversation and speaking in acronyms. Most in the class were not listening to all the details because none of us had the local A, A, & I dictionary. As it turned out neither did this two individuals. After 20 minutes of speaking about a particular A, A, or I they realized each other’s A, A, or I was completely different and unrelated to the other. Yet until they realized it, you would have been convinced they were on the same topic.
I have learned to take most news reports with a pound of salt. The VW diesel scandal may deserve at least a pinch of salt. That is my take from the attached article, “VW Dieselgate…”
Most who have taken exams to receive their medical, law, or engineering licenses would likely not pass the exam on any given day as normally administered. I am sure I could solve a sufficient number of problems to get a passing grade on a PE exam but not in the 8-hour window.
In the real world, our clients or employer would like us to work quickly and arrive at a correct solution. Few will expect you to work at the breakneck speed, required in exams, to solve problems where health and safety are involved. Demonstrating your understanding of the concepts is required but not sufficient as it may be under exam conditions. Testing, whether of machines or people, is artificial. Until you have attempted to test real world conditions, you cannot appreciate the difficulty.
Part of the artificial or “cheat mode” associated with testing people is to have specific books at arm’s length and to have recently used these books and specific charts and tables. Some hire tutors, attend special review classes, use study guides that cover the expected topics. Most of this will not be at the professional’s side after the exam. Much of the exam material will not be addressed in our day-to-day work. Most will find their job focuses on a particular product or technology. They may find themselves in administrative roles not addressed on the exams they took to receive the required certification in their field.
We accept and understand the lack of correlation between exams and real world conditions. So what is the point of testing? Some benchmark is required and this is the best we know - no one suggests cheating.
If we wish to test in real world conditions, whose world will we choose? Sticking with just automobiles within the USA, the environment for a car in Florida is very different from a car in Wyoming. As I address in my blog “Engineering From Behind the Bushes” 6/3/2015, http://www.jagengrg.com/blog correlation between test and real world is never 100% and may not exist at all. In that example, there was some real cheating on top of the known lack of correlation.
I cannot help but see a parallel between the inherent flaws in testing methods used for people and those used for machines. We establish a goal and we design to that goal. Is this criminal or a solution to an otherwise impossible set of goals? Before we crucify VW et al., would it not be better to educate the lawmakers about the impossibility of testing to real world conditions? That would be a step towards creating standards, which achieve the desired goals. What do you think?
My answer to that question would have been yes, and like all absolute answers, it would prove to be incorrect. An axiom in manufacturing is that the design engineer should not dictate manufacturing processes unless it is vital to the function of the design, metal vs. plastic, casting vs. forging etc. Once passed the gross requirements, dictating which machine tool to use would be beyond the design engineer’s prerogative unless there was a compelling reason! However, this should not be taken as the design engineer not learning all he can about manufacturing.
Requirements come in three major categories. Those we know need special attention, those we expect to happen as a matter of course, and those we did not know existed. If we need a very tight tolerance, we will call it out in the documentation for a specific feature. For the second category, we rely on title block tolerances or good machine shop practice. Those that fall into the third category are discovered when a product has been in production for a while and then a seemingly benign change is made. Often the original design team is no longer in place. Whether the original team thought a requirement in the third category was covered by the in the second category may not be possible to determine.
Products go through a test phase to weed out the unknowns before release, but revisions don’t always get the same scrutiny. Here is an example where after hundreds of thousands of units produced a change in manufacturing process caused a failure.
The product was a servo assembly that has a 200:1 reduction. It was smaller than a pack of cigarettes and the small DC motor had very little torque at the motor output shaft. I think a person could stop the shaft by hand. Two hundred reductions later there was no way you could prevent rotation at the output of the servo assembly with your bare fingers.
Some changes in the manufacturing facility resulted in a turned part being produced on a mill. The part can best be described as an axle with a flange. When the part was turned the figure on the left resulted. The concentric lines represent the fine spiral grooves on the face of the flange produced by the cutting tool when the part was turned. The figure on the right shows the fine swirl marks from an end cutter that circled the axle projecting out of the view towards the reader.
The surface finish on the flange face was never specified having it fall into category two. How much friction resulted was never established or never documented because turning produced an assembly that worked. The consultants who designed the servo at the start up of the company were long gone. The new surface condition produced by the end mill increased the friction to the point that the servo would stall. The surface in question was close to the motor so the torque at this interface was not much more than the motor output and a long way off from the 200:1 final reduction.
There are a few lessons here:1) minor changes are not always minor, 2) good shop practices are a risky thing to rely on, 3) when something stops working look for the third category of requirements, 4) ask yourself what exists in a part that is not defined or inspected, 5) the design engineer needs to be close to manufacturing even when he needs to remain silent on process selection, 6) manufacturing should notify engineering when changes are made to a process that has been in place for a long time.
I wish I could claim credit for discovering the cause and fix but a very sharp manufacturing engineer named Bob C residing at headquarters identified the cause.
When something goes wrong in manufacturing after a long period with no issues we ask “who went on vacation.” Once that is out of the way we go to the drawings to get re-educated. Yep all the callouts are OK. But you continue to stare at the drawings looking for the problem source. The manufacturing engineer is contacted and he checks his shop paper. Machines have all been calibrated, correct cutter/abrasive is called out, and incoming inspection paperwork indicates material received is OK. The manufacturing engineer even sends you the paperwork he just read to you over the phone for you to also stare at. All looks ok on paper but we gaze at the paper wondering what we missed.
An important thing to remember at the start - the paperwork is the should-be not the reality of what is. In the case that follows the problem was a leaking oil seal. Customers of new vehicles were reporting leaks for a design that had been in production for years with no issue.
On rotating shafts with seals, the lead on the surface of the shaft (like the threads on a screw but tiny) produced during manufacturing is a critical item to control or prevent. For this case the shaft was plunge ground to avoid lead (tiny spiral grooves). That is what the drawing called for and that is what was being done. Fine grooves produced by grinding are not detectable by the eye so off to the lab the parts were sent. The profilometer did not pick up any lead. Puzzled at first someone recalled a method for detecting lead that sounds like black magic since the machines in the lab detected nothing. Drape a piece of thread over the shaft which is in the horizontal orientation. The thread is weighted on each end and the shaft rotated. If there is lead the string will move along the length of the shaft. Sure enough the string moved and the lead had a twist orientation that would pump oil out and cause a leak. But how can this be - the paperwork does not allow it and the machines is set up to prevent the creation of lead.
The operation was semi automated as I recall. The part was loaded by hand and the plunge grind was preprogrammed.
Anyone willing to venture a guess as to the cause? Check out this posting next week for the rest of the story.
I have often said to young engineers that the tools we have today were not even science fiction when I first graduated. Now a 3D CAD system can easily create complex shapes. Before the 3D programs there where products with complicated shapes. This video explains how cars were designed and the number of man hours that went into it. This old video was the closest I ever got to the advanced design studios. This was high security as indicated in the video. When I look at designs of many old products and realize the tools that did not exist then I realize how many skills are today lost. You may recognize the car towards the end of the video.
This is a follow-up to the article Anticipating Abuse and Misuse of Equipment and Balanced Designs. Here is where the design engineers thought they had a balanced design.
This story took place in Germany and told to me by a very senior engineering manager in the USA. The events may date back to the 1960’s or early 1970’s but the lesson is timeless. The warranty repairs for cars made in Germany by the American subsidy in Germany and driven in Germany were having unusually high manual transmission failures in particular regions of the country.
A US warranty manager and the German engineering manager met in Germany. Somehow, each of them decided to demonstrate driving ability and technique. How much was added to this story is lost in time but it makes for a great story.
The German manager gets into the car and puts on his driving gloves. Pulls them tight and snaps the cuffs closed. He then accelerates at maximum rate without spinning the wheels demonstrating his mastery of clutch and throttle control. He shifts beautifully through all the gears maintaining RPM and never a grind or a missed shift bringing the car to the track’s maximum speed.
The US manager gets into the car and asked the German to ride with him. The US manager needs “no stinking driving gloves.” He starts the engine, depresses the clutch and stomps on the throttle. With the car standing still and the engine screaming he side steps the clutch burning rubber for a great distance before the tires fully grip the road.
The German manager yells over the scream on the engine screeching tires “No vun thrives like dis” (excuse my poor German accent). To that, the US manger replied they sure do in the USA!
This was in the days of muscle cars* and stop light racing in the USA. There were few places in the USA with roads having Autobahn speed limits. The cars made in the USA for the USA had very strong lower gears and lighter top end gears because of brutal starts and lower highway speeds. In Germany, the drivers got their kicks at high speeds 60-100+ MPH while folks in the USA did it 0-60 MPH. So the US and German cars were balanced for their markets - but it is a small world after all.
To avoid giving away the ending, I delayed fully explaining what made the high failure rate doubly unique. The high failures clustered around US military bases. The US soldiers (who may have had a muscle car back home) would rent the locally made vehicles while on leave and drive them as they drove their muscle cars. The lower gears on the German transmissions were not designed for such extreme impact and were lighter than what the US engineers would have designed for the US driver. Similar but reversed thinking for the upper gears.
Here I would like to touch on two subjects that came together during a single project. 1) Anticipating abuse of equipment and, 2) balanced designs. Abuse is self-explanatory. I use the term balanced not in terms of center of gravity but a design that has all components of similar strength or life expectancy. No single component is excessively weaker or stronger than the rest of the system.
A little background is required before the real world example.
A balanced design suggests there are no significantly weak or strong components in a system as compared to the rest of the system. For example, a well-maintained engine can operate for hundreds of thousands of miles before rebuild. If this were true except for one component, say a timing chain requiring replacement every 10,000 miles this would be an unbalanced design. An external timing belt requiring replacement every 60,000 miles may be acceptable since replacement is easier and it lasts 6 times longer than the first example. There must be some tradeoff for using a 60,000-mile belt vs. a timing chain and creating a weak link.
Weak links do exist and with good purpose, tires for example. My vehicle has traveled over 200,000 miles on the original engine and transmission but I have lost count of how many sets of tires and brakes I have replaced. Some weak links are desirable because they provide superior performance. Traction in a variety of road conditions, comfort of ride, and road noise are tradeoffs over rock-hard 200,000 miles tires. These are known and acceptable tradeoffs.
Returning to the engine as an example, a high quality high production engine may have all the components designed specifically for that one engine. A less expensive engine (any system) may use a large portion of existing parts originally designed for another applications or no particular application. Some may be much stronger than required but still be economical to use due to mass production of the component. Other components may be marginal requiring replacement one or more time before the entire engine is worn. For a one-of-a-kind device addressed below the attempt at a balanced design can really go out the window if ever considered.
A few years ago, a client received a unique order for a very large volume of a specific component. The component normally shipped within a complete assembly with only a limited number of this particular component per assembly. The labor of loading tens of thousands of these 300+ lb items on to railroad flat cars was a bottleneck never before experience by the client.
The client designed a beam that lifted 25 components at a time. Since this was a one-off design, there was no optimization performed to balance the design. What came with that approach was a potential safety hazard.
The staff purchased off-the-shelf cables with a lift rating of 1,000lb each and fabricate the lifting bar with 25 attach points. The cables were available at the local supply store. The danger here is that each set of cables has a rating tag indicating 1,000lb capacity. A worker not familiar with the design may assume the lifting bar could take 25,000lbs. The unbalance in this lifting device comes in the middle of the system. Each of the cable sets (2 legs x 25 sets) was good for 1,000lb. The overhead gantry crane was 20 or 40 tons. The weak link was the lifting beam, which was well below a 25,000lb capacity if a high factor of safety was maintained.
When equipment is being assessed or designed, the engineer must endeavor to find likely methods of abuse, misuse, and safety issues. My final report emphasized the unbalance and potential safety issue. Shortly after submitting my report, I spoke to the client’s safety engineer. He said one of the worker suggested using the lifting device for (25) 1,000 lb components. Exactly what my caution predicted could happen.
In this example, the abuse of an unbalanced design would not just result in an early repair due to a weak link, but could have resulted in deadly accident. The weight capacity marked on the cables and the overhead crane provided a false impression of system capability.
This story recalled another incident that demonstrates that a balanced design can develop a weak link depending on use of the system. I will save that for another article.
As a young engineer I had just completed a lot of book learning and of course turned to my books for solutions once on the job. I have witnessed a similar focus on computer tools as 3D CAD and FEA. Both are valuable tools but you must understand the problem before the tools are applied.
During my early days as a mechanical engineer in the auto industry the Japanese where taking market share at an alarming rate. Motown was scrabbling for an explanation. Statistics became the jargon of the day and Dr. Deming a living legend. The company offered an applied statistics course titled Design of Experiments which was taught by the coauthor of the text. The coauthor was of the PhD type but taught us a practical lesson I have carried for over 35 years and will share with you shortly. First some background.
One method of testing vehicles back then and perhaps still today is to have a test track with permanent potholes and other brain jarring features. Technicians would drive the cars for many laps accumulating about 28,000 miles in a relatively short time. The cars were then taken apart and all the components checked for wear and damage. Now 28,000 may not sound like much but if you drive at just the right speeds over a road paved the cobblestone (in their natural form) you can get the car and its content to resonate and that included the un-expecting engineer going for a ride-a-long. That was only one part of the course the car travelled. Most engineers did not do ride-a-longs on a regular basis.
The engineer teaching the class told us that there was no real correlation between the damage the cars sustained during the 28,000 mile test and wear from normal use. But tests of this type did identify weaknesses that could be addressed.
This is where the mystery starts. There were two identical tracks. One located in Michigan and another in Arizona. Though there was no correlation between the test results and the real world use, correlation between the two test tracks was expected. The cobblestones and the steel lined pot holes were the same for both tracks as were the test procedures and driver training. So what could be the cause for this variance?
Michigan is cold and damp and Arizona hot and dry. Was it the natural environment? Was the salt used during winters in Michigan getting onto the test track? All the obvious possibilities were eliminated. Then the statistical tools were brought to bear with no better success than the climate study. I shudder to think of what tools and resources that would have been employed today because of their abundant desktop availability and the WWW.
Well when all else fails and the boss wants an answer, you need to abandon the comfort of the office, get on a plane, and see things firsthand. Now if you know anything about psychology, people perform differently when being watched. To learn the real or typical behavior of people you need to observe from “behind the bushes.”
The mystery had a very simple explanation. Those who were thousands of miles from watchful eyes decided the cobblestones and steel lined potholes hurt their backs so avoiding them was a better alternative.
This is a true story as told to me. The point of presenting here is that the analytical tools we have are a marvel but can truly be a diversion from reality. The tools are only good when the correct input is provided. The tools today are so easy to use and data output so impressive we may not stop and think if the input we provide is correct. Even back in the dark ages of my beginnings a lot of time went into analyzing something that only hiding behind the bushes would reveal. So before all the analysis goes into play make sure you understand what is being analyzed. GIGO was true then and true now.
I have been encouraged to contribute to the Mechanical Engineering web site by Dr. D. I have started the blog "Not Taught in Class". The purpose of the blog is to provide examples of lessons learned in the field that you would not learn in class. These stories are not white papers, just real life examples of things not expected and problems solved. The blog postings will also attempt to provide insight and perspective that comes with many years in the field of engineering. I hope the blog postings will be informative and in many cases entertaining.