RE: Digest Number 46

Kent,

 

Great post.  

 

I'd like to add that the people in the Lean Construction Institute would
not agree with the statement that rushing building construction
invariably damages its long term value.  In fact, they show that
focusing on flow rather than thinking of each task as separate increases
the quality of a building.  

 

As Womack says in 'The Machine that Changed the World:'  "We suggest
that 'faster is dearer' will now join 'quality costs more' on the junk
heap of ideas left over from the age of mass production."

 

Mary Poppendieck

www.poppendieck.com <http://www.poppendieck.com/>  

952-934-7998

 

 

   Date: Sun, 19 Jan 2003 08:27:29 -0800

   From: "Kent Beck" <[email protected]>

Subject: RE: is SIP an Emergent Property

 

"Rushed building construction invariably damages the artifact's long

term value. Customers who would rush software production are causing

even more damage. Software ought to be a long term expense: kin to brick

and mortar, or to machinery. No sane culture rushes into making their

long term considerations, and investments."

 

There are three causes of long development cycles:

  * Essential -- you just have a lot to do.

  * Accidental waste -- these are activities that add value, but the

value could have been added some other way using less time. The testing

phase after development is "finished" is an example. If you could

develop without creating all those defects, you could shorten the cycle

by eliminating the testing phase.

  * Pure waste -- these are activities that don't add value at all, like

waiting for the testing machine.

 

Lean development has discovered that in-process inventory is an

excellent canary in the coal mine to discover the presence of waste.

Crank inventory down until it hurts. Back off. Figure out why it hurt.

Eliminate the waste. Crank inventory down further.

 

If someone tried to rush development, it would hurt too much and they

would back off. That's not what we are talking about. Ohno says, "Every

worker must be a turtle." That is, if anyone is rushing, they are doing

the wrong thing. They should slow down, figure out why they were

rushing, solve that problem, and then they will be able to produce as

much as before or more, but without rushing.

 

Kent