Re: Re: Responsibility

On Sunday, December 15, 2002, at 3:00:16 PM, Charlie Poole wrote:

>> Here's a question: consider a project that assigns a dollar value to each
>> story, and another project that only knows, for any pair of stories, which
>> one is worth more.

>> What differences could we detect in the decisions made in these 
>> two projects?

> Lovely question.

Thanks. I was rather proud of it myself. ;->

> In the planning exercise that you do - although you weren't
> there when I did it with Chet and Anne - we discovered that
> knowing the actual value function would allow optimizing the
> order of doing stories so that the most value was delivered
> first. The actual measure to optimize was the ratio of the
> value points to the level of effort points.

Ah, but consider the question further in the light of that game. I suggest that
always knowing which story is larger may be sufficient to optimize almost all
the way. And certainly knowing any linear scale (this one is twice as valuable
as that one) would suffice, would it not?

> However, the results that we came up with using only rankings
> were within a few points of the optimum and about twice - if
> my memory serves - the value we created without any information
> given in advance.

> So having perfect knowledge of the "real" value of each story
> should give us a slight improvement over having only rankings.

> The problem with this is that perfect knowledge of value is
> really not reachable - nor is perfect estimation of effort which
> also plays in the optimization formula. I'd guess that normal
> variations in both estimates would pretty quickly wipe out
> any theoretical advantage. Combining that with the cost of
> coming up with estimates of value, I pick simple ranking as
> the winner.

> This doesn't say anything against the usefulness of Cost/Benefit
> calculations done in advance of approving the whole project.
> In that case, we are looking at the expected value of the whole,
> which is probably something more than the sum of the parts, and
> the central limit theorem is standing by to help us out.

Exactly!

Ron Jeffries
www.XProgramming.com
It's easier to act your way into a new way of thinking
than to think your way into a new way of acting.  --Millard Fuller


------------------------ Yahoo! Groups Sponsor ---------------------~-->
Get 128 Bit SSL Encryption!
http://us.click.yahoo.com/CBxunD/vN2EAA/xGHJAA/NhFolB/TM
---------------------------------------------------------------------~->

To unsubscribe from this group, send an email to:
extremecustomering-unsubscribe-hHKSG33TihhbjbujkaE4pw@public.gmane.org

 

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/