I don't force it 5x but asking why was the best lesson I learnt working with users/clients as people tend to talk about solutions and not the problems. That's also where my nickname comes from.
Why is there no filter on the intake? It was proposed, but declined by management as "too costly".<p>Why is it too costly? Because cutting visible costs is <i>perceived</i> as saving money and therefore Good, whereas prevention and maintenance are perceived as unnecessary, because Bad Stuff Just Happens Regardless.<p>Why? Because people suck at statistics ("if we can't eliminate a risk altogether, there's no point in trying, let's just forever keep fixing the fallout") <i>and</i> because Fixing Broken Stuff Is Someone Else's Budget, Let's Pass The Buck.<p>(Or at least, that's the way things tend to turn out when you decide to go beyond the immediate cause-and-effect)
There seems to be some confusion/mis-interpretation about the 5 part.<p>This is called 五回のなぜ in Japanese ("Go-kai no naze," or Why Five Times) and refers to root cause analysis. Of course the number of times the process need be repeated until the root cause is identified is variable. Five in this case is merely a jingly mnemonic, as Japanese people are so fond of.
I know a certain 3 year-old who uses a similar trick to collect knowledge about the world. Not being sarcastic here; orgs can learn a lot from young children about how to acquire new skills and make decisions in the face of uncertainty.<p>Before they can even walk infants learn to judge whether they're about to crawl off a cliff -- a skill the yahoo board (for example) could have really used.
I survived several years in a Six Sigma organization. The Five Whys was one of my favorite 'tools' despite the 'Black Belts' dragging the process out much longer than required.<p>I've never seen a methodology burn through more easel pads.
"Why do vehicle manufacturers lie about emissions?"<p>"Why do vehicle manufacturers lie about emissions?"<p>"Why do vehicle manufacturers lie about emissions?"<p>"Why do vehicle manufacturers lie about emissions?"<p>"Why do vehicle manufacturers lie about emissions?"
I preach this whenever i can in regards to social issues. Whenever one of your friends, or any person, acts in a way that you don't agree with (being rude, sleeping around etc), be patient and try to think about possible underlying causes; it's much more fruitful to engage the underlying unhappiness (carefully) than to react hastily to the immediate situation.
Reminds me of Feynman's answer[0] when asked about magnets.<p>0.<a href="http://youtu.be/MO0r930Sn_8" rel="nofollow">http://youtu.be/MO0r930Sn_8</a>
Sometimes I have multiple solutions to a problem in mind and want to throughly investigate them, but run into a minor road block when investigating one of them.<p>In forums, some of the most annoying threads are people that are trying to help you "solve your real problem" instead of helping with the specific question at hand.
I have read Ohno's book. <a href="http://www.amazon.com/Toyota-Production-System-Beyond-Large-Scale/dp/0915299143/ref=sr_1_1?ie=UTF8&qid=1462802966&sr=8-1&keywords=taichi+ohno" rel="nofollow">http://www.amazon.com/Toyota-Production-System-Beyond-Large-...</a><p>One thing that stuck out to me was how long everything took to figure out on the Toyota Production System. Ohno spent decades streamlining processes. The timeline is in the inside cover of my copy of the book.<p>Fascinating read, and easier to read than some other "Toyota Production" books written by academics. Recommend.
Keep pressing next on that page to see a few more bite size pieces of Toyota wisdom. They won't change your life, but for 30 seconds or so you'll associate Toyota with intelligence and innovation.
Why 5x?
You should rather check when you reached the point that it will not happen again.<p>Probably nobody is assigned to the task of installing filters in new machines and the next one will fail again...
1. Why is Toyota accelerator-pedal drive-by-wire code a spaghetti mess of impossible to debug code?<p>2. Why still? 3. Why still years later? 4. Why a decade later? 5. Why not fix it?<p><a href="http://www.edn.com/design/automotive/4423428/Toyota-s-killer-firmware--Bad-design-and-its-consequences" rel="nofollow">http://www.edn.com/design/automotive/4423428/Toyota-s-killer...</a><p>This is why my car is the last model with mechanical accelerator and steering.
The first time I heard about this was from Joel Spolsky of Fogcreek/Stackoverflow. It really changed how I've approached postmortems and encouraging those to really drive deeper into problem solving. <a href="http://www.joelonsoftware.com/items/2008/01/22.html" rel="nofollow">http://www.joelonsoftware.com/items/2008/01/22.html</a>
Ask why more than twice at my job and you'll get in trouble. Sometimes the boss, and the customer, doesn't want to be asked. I think this idea is too aggressive and indicative of high pressure sales tactics.
"Why?" is a fine response to a statement of intent; but "How do you know that?" as a response to a declarative statement used for motivation can often be more enlightening.<p>(This kind of epistemological work-out is handy in lots of other situations. When the JWs or Mormons show up at your door, asking "How do you know that?" repeatedly is often all that you need to do until they give up and go away.)
5 whys is my go-to debugging strategy for truly mysterious software and systems bugs.<p>The rubber hits the road at the point where you have an answer like "one of A, B, or C occurred" and you don't know which because none of them are ever supposed to happen :) you know you're within a clue-bat-swing-radius of the problem then.
I believe Goldratt suggested something like "ask why until the answer is a feeling" which is much in the same vein as the five whys. For anyone wanting to learn tactical approaches to root cause analysis, lookup Goldratt and ”reality tree", profound life/career/wealth changing stuff.
"Why" is my favorite question. It's also the most important and leads to solutions for 9/10 problems if you just keep asking it. Stop when you get to the root cause that you can fix (not some arbitrary number like 5).
Wow, Toyota being given some love?! I thought there was a blanket ban on all things Toyota so the community isn't forced to admit that all things agile are actually from the manufacturing industry, decades ago. Where might this lead? Might we be forced to consider that much has been borrowed from architecture? Or math? But then, it will be so much more difficult to feel good about dwindling list of contributions software programmers have born to the world.
Pity they don't believe in this in real life.<p>Why does the hybrid braking system and mechanical braking system disengage with ABS, but then only re-engage the mechanical brake, resulting in a considerable change in deceleration, causing you to have to depress the brake further to avoid colliding with things in front of you.<p>Still waiting on a good reason for that one...
I have just have one 'why':<p><i>Why is Japan's GDP growth looking like this:</i> <a href="http://www.tradingeconomics.com/japan/gdp" rel="nofollow">http://www.tradingeconomics.com/japan/gdp</a><p>Not that I don't like posts about management techniques but from Toyota (their best years are also some time ago) from Japan... I don't know.