[SystemSafety] Another question

[Paul Sherwood]

On 2018-09-20 21:42, Steve Tockey wrote:
> ³You cannot claim that just because some factor contributed the largest
> amount, that this was somehow bad.  What were the alternatives?²
> 
> When that one largest factor is rework, yes I can.

Not necessarily. As much as I think the Agile folks are/were snake-oil 
salesmen, we can't expect to "get it right first time" for most serious 
human endeavours. In fact not even for tiny endeavours... try turning on 
a key logger and then replaying your own keystrokes to see how many 
errors you make.

Our initial understanding of the requirements ** will be wrong **.

> Rework, in the Deming sense, is waste. It does not add value to the
> product being built or maintained.

Tough. Better add contingency then :)

> Requirements, design, construction‹and
> to an extent‹testing work had better add value. The clear alternative 
> is
> to replace non-value-added work with value-added work.

This 'alternative' has never been clear on any real-scale project I've 
encountered in my whole career.

> 60% non-value-added work cannot be the cheapest and fast way to 
> anything.

Possibly true, but maybe not. We are short of evidence, as has been 
expressed in other emails.