Re: [SystemSafety] Data on Proof effectiveness from real projects

From: Steve Tockey < >
Date: Sat, 2 Apr 2016 18:45:46 +0000


PBL wrote:

"Well, that sort of depends on what the words are taken to mean. As I read it, you're missing a
parameter of achievement, of output. Maybe you hid it in the concept "work", but if so then I'd
suggest that's not a helpful way of expressing it."

I thought achievement was obvious in the term "work done". Work not done--either because it was never started, or because it was never correctly finished--can't contribute to either efficiency or effectiveness.

-----Original Message-----
From: systemsafety <systemsafety-bounces_at_xxxxxx on behalf of Peter Bernard Ladkin <ladkin_at_xxxxxx Date: Saturday, April 2, 2016 12:36 AM
To: "systemsafety_at_xxxxxx <systemsafety_at_xxxxxx Subject: Re: [SystemSafety] Data on Proof effectiveness from real projects

On 2016-04-02 07:37 , Steve Tockey wrote:
> Generally speaking, efficiency is looking at investment per unit of work
>done.

Well, that sort of depends on what the words are taken to mean. As I read it, you're missing a
parameter of achievement, of output. Maybe you hid it in the concept "work", but if so then I'd
suggest that's not a helpful way of expressing it.

For example, take the production function in a simple form. Product = F(Labor, Capital). An
economist would understand "investment" = Capital, "work" = Labor. "Efficiency" is, amongst other
things, a measure of how much Product is produced for a given input of Capital and Labor. Our
economist would ask where the "Product" bit appears in your formulation.

Actually this ties in with a recent experience. The UK government statistics agency wants to improve
its assessment of the contribution of ICT to national productivity, which thoughtfully involves
consulting with engineers. So a few of us sat in a symposium with some statisticians and what I
later figured out was the cream of the UK's productivity econometricians. The kind of people who
introduce themselves with "hello, I'm Nick and I work at the LSE" and proceed to make occasional,
spare remarks of casual brilliance, each one showing me I know even less about econometrics than the
nothing I thought I knew. Finding myself occasionally surveying the corners of the room for the most
convenient crawl space.

Fun, though. I went in thinking I nominally understood the briefing papers, and came out really
understanding them. That's always fun.

PBL Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany
Je suis Charlie
Tel+msg +49 (0)521 880 7319 www.rvs.uni-bielefeld.de



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systemsafety_at_xxxxxx Received on Sat Apr 02 2016 - 20:45:55 CEST

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