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Re: [scrumdevelopment] Like to do Scrum certification, please guide me

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  • David Starr
    +1 to Ron s comments. Sorta. Spending so much effort on estimation is a sure sign that the overall system is optimizing for certainty. If that s what s
    Message 1 of 18 , Jul 3, 2012
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      +1 to Ron's comments. Sorta.

      Spending so much effort on estimation is a sure sign that the overall system is optimizing for certainty. If that's what's happening, you are probably not getting from Scrum what you wish you were.

      If you really want to become more accurate, allow yourself to be less precise. For example, mature Scrum Teams sometimes enjoy just counting PBIs delivered per Sprint instead of summing estimate values for them. Makes sense to me: Measuring instead of estimating almost always makes sense.

      If you are in a world that focuses on estimates as being important, you are probably working on boring problems. That's what Kanban is for :)

      David Starr
      Scrum.org, Chief Craftsman - Improving the Profession of Software Development
      elegantcode.com | @elegantcoder  | scrum.org | @scrumdotorg




      On Tue, Jul 3, 2012 at 1:37 PM, RonJeffries <ronjeffries@...> wrote:
       

      Hi Steve,


      On Jul 3, 2012, at 12:51 PM, Steve Crago wrote:

      He also states on page 71, "Story points are a pure measure of size.  Ideal days are not."  

      People keep saying things like that. I do not understand them. What is "size"? What is "complexity"? And who cares? What people are trying to do is figure out how much work to take on. That comes down to how long the stuff takes, as I see it.

      Ron Jeffries
      www.XProgramming.com
      I try to Zen through it and keep my voice very mellow and low.
      Inside I am screaming and have a machine gun.
      Yin and Yang I figure.
        -- Tom Jeffries


    • Kurt Häusler
      Hi when I read it I was expecting him to warn against rather than sanction equating story points with ideal man days. Another example was calculating a teams
      Message 2 of 18 , Jul 3, 2012
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        Hi when I read it I was expecting him to warn against rather than sanction equating story points with ideal man days.

        Another example was calculating a teams initial velocity by estimating each individuals velocity and adding them up.

        I don't want to be too harsh or critical, there is a lot of good stuff there, but I think it might have looked better when it was written than it does now.

        I feel that the few sprinkles of questionable things in his books are exactly the sort of things people latch onto and use to justify strange practices, and they spoil the rest of the good stuff in the books.

        Anyway that was just my impression from reading them.

        Glad to hear his recent courses are worthwhile, I would like him to look at and update his books though.

        On Jul 3, 2012, at 6:51 PM, Steve Crago wrote:

        >
        > Kurt:
        > Looking at my copy of "Agile Estimating and Planning" and my copy of the course material by the same name, I don't see where he treats story points as ideal days, in fact it is just the opposite. On page 69, the title says it all "Chapter 8 Choosing between Story Points and Ideal Days". He starts out talking about story points, afterwards he discusses ideal days. He then goes over the pros and cons of both processes and provides his recommendation, which is to use Story Points. He also states on page 71, "Story points are a pure measure of size. Ideal days are not." In his summary of the chapter he states "A team can choose to estimate in either story points or ideal days. Each is a viable choice with advantages to recommend it."
        >
        > Hopefully I haven't misinterpreted your response "Treating story points as ideal man days was one example, but I remember coming across a few more." I'm not sure where or how you got this idea and would be interested to know where it came from so that I might expand my own level of knowledge.
      • Charles Bradley - Scrum Coach CSP CSM PSM
        Kurt, You mentioned a couple of examples of questionable things in Mike Cohn s books. Specifically,  === Treating story points as ideal man days was one
        Message 3 of 18 , Jul 14, 2012
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          Kurt,

          You mentioned a couple of examples of questionable things in Mike Cohn's books.

          Specifically, 

          ===> Treating story points as ideal man days was one example,

          I found this in _User Stories Applied_,  so here is the actual quote with more context:
          <quote>
          An approach that satisfies each of these goals is to estimate in story points. A nice feature of story points is that each team defines them as they see fit. One team may decide to define a story point as an ideal day of work (that is, a day without any interruptions whatsoever—no meetings, no email, no phone calls, and so on). Another team may define a story point as an ideal week of work. Yet another team may define a story point as a measure of the complexity of the story. Because of the wide variety of meanings for story points, Joshua Kerievsky has suggested that story points represent Nebulous Units of Time, or NUTs.[1]
          [1] Joshua Kerievsky on extremeprogramming@yahoogroups.com, August 5, 2003.
          My preference is to treat a story point as an ideal day of work. We rarely have these ideal days, but thinking about stories in ideal time offers two advantages. First, it is easier than estimating in elapsed time. Estimating in elapsed time forces us to consider all other possible impacts on our time, such as the all-company meeting on Tuesday, my dentist appointment on Wednesday, a few hours a day for answering email, and so on. Second, estimating story points in ideal time gives our estimates a slightly better foundation than when they are estimated in entirely nebulous units. Since one of the main purposes of estimating is to be able to answer questions about the overall expected effort in a project, we will eventually need to convert estimates into time. Starting with ideal time makes that conversion a little simpler than starting with an entirely nebulous unit.
          </quote>

          I tend to agree that this information is outdated, though I don't think it is particular dangerous, either.  I also don't think it spoils the rest of the goodness in the book.  I think my view on this is that the book should mostly be consulted for its info on User Stories, and I would prefer Cohn's later book _Agile Estimating and Planning_ for topics on Scrum and Velocity implementation practices.  I mean, he clearly inspected and adapted his advice in the time between the books.

          ===> Another example was calculating a teams initial velocity by estimating each individuals velocity and adding them up.

          I was unable to find this one.  Can you point me to where you saw that?
           
          -------
          Charles Bradley
          http://www.ScrumCrazy.com




          From: Kurt Häusler <kurt.haeusler@...>
          To: scrumdevelopment@yahoogroups.com
          Sent: Tuesday, July 3, 2012 9:02 PM
          Subject: Re: [scrumdevelopment] Like to do Scrum certification, please guide me

          Hi when I read it I was expecting him to warn against rather than sanction equating story points with ideal man days.

          Another example was calculating a teams initial velocity by estimating each individuals velocity and adding them up.

          I don't want to be too harsh or critical, there is a lot of good stuff there, but I think it might have looked better when it was written than it does now.

          I feel that the few sprinkles of questionable things in his books are exactly the sort of things people latch onto and use to justify strange practices, and they spoil the rest of the good stuff in the books.

          Anyway that was just my impression from reading them.

          Glad to hear his recent courses are worthwhile, I would like him to look at and update his books though.

          On Jul 3, 2012, at 6:51 PM, Steve Crago wrote:

          >
          > Kurt:
          > Looking at my copy of "Agile Estimating and Planning" and my copy of the course material by the same name, I don't see where he treats story points as ideal days, in fact it is just the opposite.  On page 69, the title says it all "Chapter 8 Choosing between Story Points and Ideal Days".  He starts out talking about story points, afterwards he discusses ideal days.  He then goes over the pros and cons of both processes and provides his recommendation, which is to use Story Points.  He also states on page 71, "Story points are a pure measure of size.  Ideal days are not."  In his summary of the chapter he states "A team can choose to estimate in either story points or ideal days.  Each is a viable choice with advantages to recommend it."

          > Hopefully I haven't misinterpreted your response "Treating story points as ideal man days was one example, but I remember coming across a few more."  I'm not sure where or how you got this idea and would be interested to know where it came from so that I might expand my own level of knowledge.


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