Lazeum Posted May 7, 2013 Share Posted May 7, 2013 I see a lot of topics: "please help!", "why it does not work?", etc. As a mechanical engineer, I've been following some basic methods to solve issues. As obvious as it could seem for some, it seems everyone is not following the same path. What about we try to gather methods to solve problem by ourself? I believe everyone should do his homework first prior to request some help. Most of the time, first answers from members are other questions. What about we try to provide some answers to questions instead? Of course, the first move should be to search for already known issues. there's tons of lessons learned to be shared on this board. OEM's are using some problem solving form such as 8D at GM. it helps to: - Define the issue - Prevent it (in the industry, it usually mean "check parts & scrap bad ones" ) - Find the root cause - Find a corrective action - Make sure it solved for good 2 very basic tools, one is a method "5-why", the second tool is to move forward in the process: fishbone diagram. 5-why. This is what I'm using when I have a problem: I ask myself why, why, why until I've got a root cause to solve. Usually at the 5th "why", we've got the answer. The goal is not only to solve the issue but also to prevent it to happen again. That's very basic quality process. Example: Issue: My headlights do not work. 1st why: Why don't they work? -> Bulbs are broken? - no -> Fuses have melted? - Yes -> Harness is damaged? - No, checked with ohmmeter -> Connectors are bad/corroded? - No, they look ok -> Headlight switch damaged? - No, it was in good shape -> etc. - because there's probably 10 more items to be added if we'd like. 2nd why: Why did my fuses melt? -> Fuses are too weak? - No, they were 15A (instead of 10A) -> Fuses holder is corroded? - No -> Corrosion in connectors? - No, I've checked earlier -> corrosion in headlight housing? - No + when I disconnect them, fuses no longer blow (hint!) -> I've got a wire grounded somewhere? - No, every ground is showing continuity with chassis & Engine -> I've got a short somewhere ? - I notice position light bulb (inside headlight housing in my case) is having 10V instead of ground & 12V from regular signal wire. 3rd why: Why do I have 10V & 12V at position light bulb? and why position light issue would interfere with headlights? -> Wire is damaged somewhere ? - No, everything is good as stated above. -> Because I've hacked my headlight harness to pass European regulation with +12V signal taken from side markers? Human related error? how could that be? -> Because I've hacked my headlight harness to bring a ground to position light bulb? I've got +10V instead of ground! I've added a wire going from a black wire labeled "ground" to position light bulb. 4th why: Why "ground" black wire is providing +10V instead of being ground? -> Nissan/Datsun did a mistake? -> Previous owner has hacked also the harness thus changing everything? - Obviously yes since no wire has the correct color coding when referring to service manual. -> Because I haven't checked proper tension before setting everything up? No need for 5th why here ! The causes of the issue: -> Harness has been modified -> I did not check everything while doing the work - Lesson learned! (hopefully!) -> Wires are improperly crimped together, I had to changed the way they were setup. I've controlled everything with a voltmeter during the process! Problem is solved & I'm positive it won't come back. Fishbone diagram or cause-and-effect diagram This one helps to get proposal for every "why". It starts with a consequence: "fuses have melted" for instance We should split then items into categories. the book is saying to split them into 5 major ones: People, Methods, Machines, Materials, Measurements, Environment. I don't usually follow exactly those steps. The point is to think about anything that could be the cause, it is a brainstorming step. This is where forum community could help the most. Image from Wiki: In materials, we would have broken wires & harnesses, corrosion issues, too weak fuses, etc. In Environment, we could also have corrosion, debris somewhere, salt in connectors In people, we could have fuses improperly clamped, etc. Management category here is useless With such process, we've got tons of stuff to do to make sure we don't miss anything. If everything is done right, nothing would be missed! This is how I've fixed headlights issue that was there for 3 years in my car in 2 days. I was just driving the car during summer time with day light to go around the issue Since it was pulling power from the system, my car was also stalling at red lights sometimes...call me stupid! These are also the basic tools that avoided my company to recall 300,000 cars because of issues.... Quote Link to comment Share on other sites More sharing options...
Miles Posted May 8, 2013 Share Posted May 8, 2013 (edited) Henery Ford said: thinking is hard work which is why most people don't do it. You are assuming that most people are rational problem solvers and will take time to think things out. After thirty-five years in engineering management I can tell you most people do not want to think too hard. This is why engineers are paid the big bucks i.e., to reason things out for those who can't or won't. Experienced mechanics already know about logical problem solving. There is much wisdom here: http://forums.hybridz.org/topic/109702-hybridz-is-not-automotive-101/ Edited May 8, 2013 by Miles Quote Link to comment Share on other sites More sharing options...
Domzs Posted May 8, 2013 Share Posted May 8, 2013 Henery Ford said: thinking is hard work which is why most people don't do it. You are assuming that most people are rational problem solvers and will take time to think things out. After thirty-five years in engineering management I can tell you most people do not want to think too hard. This is why engineers are paid the big bucks i.e., to reason things out for those who can't or won't. There is much wisdom here: http://forums.hybridz.org/topic/109702-hybridz-is-not-automotive-101/ Amen , brother . Most of them don't even know how things work , how do you expect them to fix the problems . I've been in auto repair business for over 15 years . I can tell you that most of them can't even describe the problems . Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted May 8, 2013 Administrators Share Posted May 8, 2013 Would it be inappropriate to suggest my wife read this? 1 Quote Link to comment Share on other sites More sharing options...
ctc Posted May 8, 2013 Share Posted May 8, 2013 (edited) As an engineer in the R&D test world, I would caution these methods like all tools need to be used properly. A lot of times the why is is not asked, because knowledge is lacking. My managers love to use the tools wrongly to justify the answers they already want to hear. We call it a budgeted witch hunt. The line about doing your work is the most appropriate. I don't know how many times I've ask senior engineers (I'm almost one myself, age wise too), why aren't we doing it "x" way and they hand me a twenty year old report of why it didn't work. Basic fundimentals can solve 90% of problems in my humble opinion. Edited May 8, 2013 by ctc Quote Link to comment Share on other sites More sharing options...
280zex Posted May 8, 2013 Share Posted May 8, 2013 Amen , brother . Most of them don't even know how things work , how do you expect them to fix the problems . I've been in auto repair business for over 15 years . I can tell you that most of them can't even describe the problems . I love some of the descriptions of possible symptoms I have heard over the years. Honestly I wish I had a video camera for some. I actualy had a customer come to my shop in Sacramento in the 90's, stating that we gave him a bad engine. It had over heated so dude decided to "add" some water via the oil fill in the valve cover. Seriously!! I had to excuse myself to the back of the shop whilst trying to not piss my pants from laughing so hard. Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted May 8, 2013 Share Posted May 8, 2013 Learned all this stuff in my system engineering class. It's sorta made my day to see it pop up on hybridz. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 8, 2013 Share Posted May 8, 2013 (edited) As ctc alludes to, "5-Why" is a knowledge revealer. After taking my first Demming Seminar, the theory of "if you can't answer why five times about anything you do, then likely you don't know what you're doing" was revolutionary to me. It tormented trainers to be sure... And what I found was, INDEED as Demming postulated, most people training you were incapable of telling you WHY they were telling you to do something a particular way! It set me forth on a course to understand "5-Why" for anything I did. (I am battling a Senior Engineer now who has had a 100% departmental personnel turnover in less than 5 years swear "the pay and compensation policy has worked fine for 30years!" Talk about CLUELESS!!!) If I don't answer why five times now, it's a function of codgery more than not knowing the next three why answers and wanting to waste time on repeating them out loud... And please..."Ishikawa Diagram"! Edited May 8, 2013 by Tony D Quote Link to comment Share on other sites More sharing options...
Lazeum Posted May 8, 2013 Author Share Posted May 8, 2013 (edited) First, Tony, I'm sorry to have made an example with only 4 why's answered I could have named fishbone diagram with its real name but fishbone is easier to remember with its shape. Ishikawa is indeed the author of such tool. We do not have all knowledge to fix everything (I wish I could!), I think it is the benefit of a huge forum, such as hbz, full of knowledgeable people to help the ones who need help. I think it should start first with how to tackle situations. At least, we can refer to this topic or "HBZ not being automotive 101". If the tool are not appropriately used, we are many that could make sure to bring back on track the analysis to make it efficient. Sometimes I see posts, I don't even want to answer, only because of the way the OP tries to fix it. I see also too many posts with shotgunning operation; one small target in the "dark", a riffle of solutions to expect to fix the issue. On topic such as "Engine power is not good" could end up with new fuel pump, new regulator, tuning session, new alternator, etc. whereas issue is due to clogged fuel filter which cost $3. (then, "why was the fuel filter clogged?" becomes the next step) What about "car do not start" followed by "spark plugs were fouled, I've changed them! Issue is fixed!" without knowing why in the first place spark plugs were fouled (= it will happen again!) I think some discipline would save time & money to all. I wasn't convinced when I've graduated from School, now I am. I'm even spending time writing posts about it! The only topic where this method does not work is with women, there's something irrational that makes 5-why analysis irrelevant Edited May 8, 2013 by Lazeum Quote Link to comment Share on other sites More sharing options...
Miles Posted May 8, 2013 Share Posted May 8, 2013 Would it be inappropriate to suggest my wife read this? I tried this once. Be prepared for the eye-roll followed by "BORING"! Quote Link to comment Share on other sites More sharing options...
Leon Posted May 8, 2013 Share Posted May 8, 2013 Would it be inappropriate to suggest my wife read this? The only topic where this method does not work is with women, there's something irrational that makes 5-why analysis irrelevant I tried this once. Be prepared for the eye-roll followed by "BORING"! Amen! "Hey honey, check this out! Pretty cool, right?" "Get off your forums and spend some time with ME!" Quote Link to comment Share on other sites More sharing options...
TimZ Posted May 8, 2013 Share Posted May 8, 2013 Would it be inappropriate to suggest my wife read this? This will necessitate using a whole 'nother set of problem-solving skills... Quote Link to comment Share on other sites More sharing options...
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