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32855Re: Help with The Inevitable Question

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  • ceezone
    Sep 25, 2008
      I agree with whatever you are saying Roy.

      But these are my observations/experience:

      1. Most project managers have, heard of/Used (even if
      poorly)/considered, Function points.

      2. Very few have heard of Use case points.

      3. Almost no one has heard of COCOMO (shame)

      Someone somewhere (blast my memory) has made a very valid point about
      estimations showing a graph which corresponds to one of a the
      economics curve of law of diminishing marginal returns. This is a
      curve of estimation accuracy.vs.effort expended on arriving at the
      estimate. I think lot of organisation forget that!


      --- In scrumdevelopment@yahoogroups.com, Roy Morien <roymorien@...>
      > Wonderful!! Apply mathematics and metrics (COCOMO-II - because
      COCOMO-I was found to be deficient and in need of improvement) and
      Function Points, which look great because of the emphasis on metrics
      and measurement and historical 'facts' ... and THEN ADD SOME
      CONTINGENCY ... which clearly indicates that all those metrics and
      measurements and estimating methods don't work very well ... and ...
      ummm ... what is the measure of 'some' in that 'add some contingency'
      bit?I'm sorry to be appearing to ridicule your suggestion, H. but ...
      well, yes, I am ridiculing your suggestion.
      > My advice to Simon would be to first ask the clients to give a full
      and accurate statement of requirements, and a clear contractual
      undertaking that if it is not stated in that specification, then it
      will not be included in the developed system. The client must provide
      that spec in sufficient detail for you to give an estimate of
      sufficient correctness. They surely are not so unreasonable as to ask
      you for accuracy without them also being accurate and correct and
      > If the existing system can be seen as being exactly what they want,
      and so can be pointed to as the spec., then one may ask the question
      Why on earth are they asking for a rewrite?
      > An interesting fact that arose from my research (albeit a
      reasonably restricted research activity to admit to the facts) into
      software estimating. I researched amongst consulting firms and
      contracting firms that represented well over 50% of the local
      industry in my home city; not one of them used COCOMO of any vintage,
      and not one of them used Function Point Analysis, and many of the
      project managers had never heard of COCOMO or Function Points. Do I
      come from the real boondocks of software projects?
      > Regards,
      > Roy Morien
      > To: scrumdevelopment@...: hmeftah@...: Mon, 1 Sep 2008 09:16:55
      +0000Subject: [scrumdevelopment] Re: Help with The Inevitable Question
      > Hi Simon,Many of my clients ask the same question. How estimate
      revamping anexisting application.You have to start from concrete
      facts: 1) your current application even it's not perfect works every
      day. 2) Your application is based on VB code, therefore this code
      isthe latest version of your application documentation.3) You know
      all functions and methods, screens, data structure andso on.4) you
      may know how long a new feature took to be designeddeveloped and
      tested.For my point of view your project is quite large so you may
      need aproof of concept phase to estimate time and budget. I think
      your gradual revamping is a good approach, upon these 4 basicfacts
      above you can estimate and budget for example section X whichwill use
      that method, that class, this sort of data structure, thisdatabase
      access. Use "playing cards" Scrum phase to estimate our teamvelocity
      at day one.Then refine your figures by using COCOMOII analysis,
      function pointsestimate and add some contingency.Good luckH. Meftah
      > _________________________________________________________________
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