[SystemSafety] Another question

[Steve Tockey]

Derek,

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.

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

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


‹ steve



-----Original Message-----
From: systemsafety <systemsafety-bounces at lists.techfak.uni-bielefeld.de>
on behalf of Derek M Jones <derek at knosof.co.uk>
Organization: Knowledge Software, Ltd
Date: Thursday, September 20, 2018 at 6:57 AM
To: "systemsafety at lists.techfak.uni-bielefeld.de"
<systemsafety at lists.techfak.uni-bielefeld.de>
Subject: Re: [SystemSafety] Another question

Steve,

> In my own work with software organizations I look at ³Rework Percentage²
>(R%): the percent of project labor hours that are spent later fixing
>things that were earlier claimed to be correct but found to be deficient.
>Estimates of rework normally average around 50%. I¹ve actually measured
>R% in five different software organizations:
> 
...
> All for a weighted average of about 62%.
> 
> This means that rework is the single largest contributor to project cost
>and schedule, and it is bigger than all other contributors combined.

So what, it may be the cheapest option.

Perhaps releasing an initial version was the cheapest and fastest
way of flushing out the unknowns.

You cannot claim that just because some factor contributed the
largest amount, that this was somehow bad.  What were the
alternatives?

-- 
Derek M. Jones           Software analysis
tel: +44 (0)1252 520667  blog:shape-of-code.coding-guidelines.com
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