5 Whys

[snopes]

Comment: For process improvement work there is a story about the "5
Whys" - ask why 5 times and you will get to the root cause. An example
that is oftern used is about the Washington Memorial deteriorating (also
heard it as Jefferson Memorial and why I am skeptical about the story).

Why - scrubbed often due to bird droppings
Why - birds eat the spiders
Why - spiders eat the gnats
Why - gnats are there when lights turned on
Why - lights turned on an hour prior to dusk

So instead of just changing bird dropping cleaning solution (or killing
the birds), the lights were turned on an hour later, thus limiting the
gnats, the spiders, the birds, the droppings and thus the cleanings (and
the deteriation).

It makes for a good example, but wondering if it is really true?

[Singing in the Drizzle]

I heard several different chains of "why" over the years in different training class. I would guess working in engineering leads to these types of training. Ever one the stories were just stories and were presented as just that a hypothetical story. I guess they learned that engineers ask the wrong question if you try to tell them it is a real story.

As for the 5 time to get to the root cause. It was aways taught to use as ask "why" until you can not answer the question any more, how ever may times that requires. That should be your root cause. Though you should never stop asking "why" because you may thing of something more and answer the question one more time.

[Tabbyclaw]

"Okay, I love you, buh-bye!"

-Tabby
the princess with claws

[Dropbear]

The problem is that the answer to the 'why' could be multiple things.

Thus in the OP re: the presidential memorial:

Why - because of scrubbing off bird droppings
- because of acidity in the rain
- because of the type of stone used to construct it

amd probably several others. Each of those will then have multiple other 'why' answers.

Such a process can be useful in looking at possible solutions but it won't always get to a clear root cause.

Dropbear

[Silas Sparkhammer]

Originally Posted by Tabbyclaw

"Okay, I love you, buh-bye!"

Involuntary explosion of loud, wet laughter! YOMANK!

Silas (baloney in my slacks)

[BoKu]

That sounds like a too-simplified version of RVS Why Because Analysis (WBA). My favorite example is this WBA analysis of the 1979 Chicago DC-10 accident.

Bob "With two to three fuel-efficient engines!" K.

[CSGirl]

They teach this in Six Sigma, we had to take the white belt training for work.

[Lainie]

From BoKu's link:

Why was the aircraft destroyed?
Because it hit the ground.

[BoKu]

Originally Posted by Lainie

From BoKu's link:

Well, yeah . It's not the fall that gets ya, it's the sudden stop at the end.

My father is fond of telling his students, "Always try to stay three mistakes above the ground."

The thing I like about that article is that it shows how formal WBA homes right in on the fact that the airplane was flyable even though one of the engines parted company and was controllable even with asymmetric slat deployment. It just wasn't controllable at the speed that the pilot chose, and the pilot was not presented adequate information about the aircraft condition to make an informed decision to fly faster. And further, that even though the systems that should have so informed the pilot "met industry standards," they and by inference the "industry standards" are inadequate.