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Re: [XP] New practice: Slack

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  • Ron Jeffries
    ... It doesn t sound like it to me. It sounds to me like you are saying we [mostly] can t know what will be done, and I m sure I m saying we mostly can know
    Message 1 of 110 , Jan 2, 2006
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      On Monday, January 2, 2006, at 2:42:23 PM, Paul Beckford wrote:

      > I think we are saying the same thing.

      It doesn't sound like it to me. It sounds to me like you are saying
      we [mostly] can't know what will be done, and I'm sure I'm saying we
      mostly can know what will be done.

      I'll see if I can make clear where I see difference in what you've
      said.

      > My general point then, is depending on the teams relationship with their
      > customer, that the customer can/should be included in the process of
      > managing uncertainty (risk). I use the term "customer" and "mangement"
      > interchangeably as the distinction between these roles vary from one
      > organisation to the next.

      Yes, certainly those people should be involved. In fact, in my
      opinion, they own the problem and ought not delegate it, as I hope
      my referenced article makes clear.

      > Infact I would go further and say that given the right information, that
      > risk management is ultimately a customer responsibility.

      I agree entirely with this notion.

      > So using probability, then over time a customer will be able to
      > determine the acurracy of the predictions (estimates) made by the
      > team. The probability distribution of predictions vs actuals
      > represents a characteristic of the team as machine. Using this
      > information the customer/management should be able to predict for
      > example how many iterations are required to have a 99% probability
      > of achieving a specific outcome.

      In practice, I think this is not the best approach. One reason is
      that the error bars even on simple estimates are far too wide, and
      another is that there are many things outside everyone's control.
      The numbers don't have to go stable to be very useful.

      The real customer/management job is to use whatever predictability
      exists to /steer/ the project to success, not just sit back and
      predict the date with their calculator.

      > If the spread (standard deviation) in the probability distribution is
      > wide, then to achieve a 99% probability will require a lot of redundancy
      > and possible waste as you point out. The customer/management then as a
      > choice to change teams, or to request improvements within the current
      > team. Through feedback the team and the customer can work
      > collaboratively to improve accuracy (e.g less interruptions for the
      > team, clear project focus, more domain expert time, the right balance of
      > experience/skill in the team etc). Ultimately if the customer looses
      > confidence in the team, or in the project then the option to cancel
      > exists (some projects just have a higher degree of uncertainty (risk)
      > then others).

      This still sounds to me like using the raw data produced by the team
      to estimate when things will be done. That is certainly not my
      recommendation. I'm recommending that management should manage.

      > So my point is why hide this information? Why not be open about how well
      > the team as a machine is performing? This allows an open and honest
      > discussion on how to improve. After all the root cause may not be down
      > to the development team. They could be problems in the organisation or
      > with the project concept, or with the customer team etc.

      As this is the extreme programming group, I would think that there
      is no intention, on anyone's part, to hide any information. I
      certainly haven't said to do that, and can't think offhand of anyone
      who has taken that position.

      > The idea of Slack just seems meaningless in this context. If certainty
      > is important then customers will add slack themselves.

      I could quite possibly be wrong, but I take the idea in the 2e book
      to be that the Whole Team (not just the developers) need to be clear
      about what they can "absolutely" commit to. They are then advised to
      leave slack between that number and the presumably significantly
      higher "might" number. They fill that slack (gap) with less
      important but still valuable work.

      That practice -- committing to what's "certain" and filling in with
      "still good to have", makes perfect sense to me. That may be what
      the book practice means: in any case, it's what I believe is a
      sensible thing to do.

      > I accept that in most organisations the degree of trust between the
      > customer and the development team is not sufficient to do as I suggest.
      > But I see that as a different issue. The issue in such circumstances is
      > how do I increase the level of trust with my customer so that I can tell
      > him the truth. Now that is a whole different ball game.

      Again, I think that one should always tell the clear and absolute
      truth about the project, as one knows it. I do think that the truth
      needs to be expressed carefully, clearly, and well, in terms that
      the listener -- in this case the business people -- can understand.

      So I'd not say, for example, "software development is complex,
      chaotic, and unpredictable, therefore we can tell you nothing about
      the schedule." That would be neither true, nor effective
      communication.

      I'd be more inclined to say something like

      Based on what has gone before, as shown in this chart, our best
      estimate is that we will accomplish between 75 and 110 items from
      this list you gave us, by the date on which you said you wanted to
      deliver. We can pretty much do any items in any order, and invite
      you to be certain that we do the most important ones first. As the
      project wears on, we'll always have the software ready to go, and
      we'll always show you the current version of the chart. Any
      questions? Let's discuss anything that isn't clear.

      The chart I'd use would look like the ones here:
      http://www.xprogramming.com/xpmag/BigVisibleCharts.htm#N190

      So ... are we saying the same thing?

      Ron Jeffries
      www.XProgramming.com
      We cannot solve our problems with the same thinking we used when we created them.
      -- Albert Einstein
    • Paul Beckford
      ... Hi Victor, I totally agree. I am a European too (I live and work in the UK), and I ve also worked in the States, and there is a cultural difference (by and
      Message 110 of 110 , Feb 12, 2006
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        Victor wrote:

        > I think this is a serious social
        >issue that needs to be confronted by society as a whole at the educational
        >level. Honesty can be tough to maintain in an environment that values
        >denial and unrealistic expectations, but in final account it's the best
        >policy.
        >
        >Victor
        >
        >
        Hi Victor,

        I totally agree. I am a European too (I live and work in the UK), and
        I've also worked in the States, and there is a cultural difference (by
        and large I find both the UK and the US very similiar though). I think
        it has something to do with the perception of science in the west and
        the role of the scientific expert. Earlier in this thread (way back)
        someone made a similar point about Doctors in the west not being able to
        say that they don't know, and presumeably experiencing emotions of guilt
        when they truly do not know.

        In software I think it is about organisational culture, and I have
        experienced cultural change by simply telling people I do not know. At
        first they are shocked, but once you encourage them to take the second
        person perspective (seeing things from your point of view), they quickly
        realise that this is the only honest answer and they respect you for it.

        With regards to the long term, many people in the west no longer trust
        Doctors and are increasingly looking to "alternative medicine". In
        China this seems to be less of an issue, as Chinese doctors are more
        willing to use approaches that aren't strictly "scientific". Maybe this
        is a tacit admission that as Doctors they do not always know the
        precise casual basis for illness and maybe as a consequence of this
        tacit admission people in China tend to trust them more.

        Just a thought.

        Paul.

        >=========================================================
        >----- Original Message -----
        >From: "Kent Beck" <kentb@...>
        >To: <extremeprogramming@yahoogroups.com>
        >Sent: Wednesday, February 08, 2006 1:48 PM
        >Subject: RE: Cultural difference was ->(Re: [XP] Re: New practice: Slack)
        >
        >
        >
        >
        >>David,
        >>
        >>The European cultures I have worked in do seem to be willing to make slack
        >>
        >>
        >a
        >
        >
        >>more visible part of the rhythms of work. Whether it is frequent espresso
        >>breaks or one-contiguous-month vacations in the summer, there seems to be
        >>more of a understanding that there is more to life than work and that work
        >>goes better when we acknowledge that. I have also seen significant erosion
        >>of this understanding in recent years, which makes paying attention to the
        >>value of slack increasingly important.
        >>
        >>As far as trust and promises are concern, if I want my children to trust
        >>
        >>
        >me,
        >
        >
        >>I will say, "I will be home at 8:30" and sometimes be early instead of
        >>saying, "I will be home at 8:00" and often being late. Whether I have a
        >>
        >>
        >good
        >
        >
        >>excuse ("traffic, you know") doesn't matter to a kid near as much as
        >>
        >>
        >knowing
        >
        >
        >>whether they can count on me.
        >>
        >>That said, I still make too many professional commitments based on what I
        >>think people want to hear and end up missing them. However, even when I
        >>
        >>
        >make
        >
        >
        >>promises I secretly think I can't meet, the big issue for me is time
        >>management. If I improved my ability to focus and prioritize I would be
        >>
        >>
        >able
        >
        >
        >>to make and meet promises with much less slack than I currently use.
        >>
        >>Sincerely yours,
        >>
        >>Kent Beck
        >>Three Rivers Institute
        >>
        >>
        >>
        >>>-----Original Message-----
        >>>From: extremeprogramming@yahoogroups.com
        >>>[mailto:extremeprogramming@yahoogroups.com] On Behalf Of David H.
        >>>Sent: Tuesday, February 07, 2006 5:45 AM
        >>>To: extremeprogramming@yahoogroups.com
        >>>Subject: Cultural difference was ->(Re: [XP] Re: New practice: Slack)
        >>>
        >>>Kent Beck wrote:
        >>>
        >>>
        >>>>David,
        >>>>
        >>>>
        >>>>
        >>>Hello Kent.
        >>>
        >>>First of all please accept my apologies for answering so belatedly.
        >>>
        >>>
        >>>
        >>>>I think software developers and managers have always
        >>>>
        >>>>
        >>>included lots of slack
        >>>
        >>>
        >>>>in their schedules. We just didn't talk about it. The
        >>>>
        >>>>
        >>>client or boss was
        >>>
        >>>
        >>>>"supposed" to think that we were working as hard as we
        >>>>
        >>>>
        >>>could 150% of the
        >>>
        >>>
        >>>>time, taking only Sunday mornings off. What happens if we
        >>>>
        >>>>
        >>>admit we are
        >>>
        >>>
        >>>>human? We take coffee breaks and time to think and look out
        >>>>
        >>>>
        >>>the window at
        >>>
        >>>
        >>>>the weather?
        >>>>
        >>>>
        >>>>
        >>>That is something, I as European, cannot quite understand.
        >>>Yes, there is peer
        >>>pressure in our countries as well, but the chances that you
        >>>get fired because
        >>>you are not working "hard enough" are pretty slim. This is
        >>>basically caused
        >>>due to our employment laws which are usually in favour of the
        >>>employee and not
        >>>the employer. As such I do not have to worry too much about
        >>>my financial
        >>>freedom or my career as long as I do pay attention to what I am doing.
        >>>
        >>>I wonder how that is influenced by the fact that I recall,
        >>>for my visits in
        >>>the USA, that this is not the case in most companies over
        >>>there. Everyone
        >>>seems very concerned how their doing is perceived by the
        >>>bosses, always aware
        >>>that they _could_ be out of work by tomorrow.
        >>>
        >>>
        >>><snip>
        >>>
        >>>
        >>>
        >>>
        >>>>What I have found for myself is that when I am open with my
        >>>>
        >>>>
        >>>customers about
        >>>
        >>>
        >>>>the process I use to make promises I feel exposed. I have
        >>>>
        >>>>
        >>>no information in
        >>>
        >>>
        >>>>reserve with which to protect myself if I break my promise.
        >>>>
        >>>>
        >>>However, when I
        >>>
        >>>
        >>>>make transparent promises, I focus harder and don't waste
        >>>>
        >>>>
        >>>time keeping track
        >>>
        >>>
        >>>>of what I am holding back, so I get more done. It works for
        >>>>
        >>>>
        >>>me, even though
        >>>
        >>>
        >>>>it doesn't always feel good yet.
        >>>>
        >>>>
        >>>>
        >>>Is this not also a matter of trust. Making promises that are
        >>>not transparent
        >>>or based on assumptions will most likely cause a more than
        >>>negative reaction
        >>>in the one you promised them too when you cannot fulfill
        >>>them. I like to think
        >>>of this like a parent promising something to their child.
        >>>When I am honest
        >>>about the possibility of failure, the child usually will
        >>>accept that when I
        >>>cannot fulfill my promise. Very similar to saying:
        >>>
        >>>I will be home by 8pm versus I will try to be home at 8pm,
        >>>but I might not be
        >>>able to be here, because the traffic will be bad tonight.
        >>>
        >>>I know that most customers will expect you to say "I will be
        >>>home by 8pm", so
        >>>how do you get out of that dilemma?
        >>>
        >>>
        >>
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