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RE: [scrumdevelopment] Re: book, "Agile Software Development with Scrum"

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  • Ken Schwaber
    I don t understand the theoretical underpinnings of why emerging architecture and design work either. A number of us that develop and practice agile were
    Message 1 of 11 , Nov 28, 2001
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      I don't understand the theoretical underpinnings of why emerging
      architecture and design work either. A number of us that develop and
      practice agile were talking about this the other day, and we agreed that:
      1. We don't know why it works.
      2. Preparing a detailed architecture and design at the beginning of a
      project is wasteful. It presupposes the requirements, often leads to
      developing technical capabilities that aren't needed (and require debugging
      and maintenance), doesn't fit with the desire to simplify, and imposes costs
      of the customer that they haven't agree to.
      3. In every case that we've relied on a stable architecture and design
      emerging, they did. Part of the reason is refactoring, but I suspect that
      the other reason has to do with team experience and the chaos theory
      "strange attractor."

      So, this is another of my research areas.

      Ken

      -----Original Message-----
      From: jonas.b@... [mailto:jonas.b@...]
      Sent: Wednesday, November 28, 2001 6:03 PM
      To: scrumdevelopment@yahoogroups.com
      Subject: [scrumdevelopment] Re: book, "Agile Software Development with
      Scrum"


      Hi,
      Emerging requirements and self-organization I can understand and
      agree to. But I have harder understanding emerging architecture. Self-
      organizing teams are just human nature, whereas architecture is a
      complex composition which is hard to change. I don't imply that
      emerging architecture is nonsense but I can't understand how it's
      possible.

      Thanks for the articles on InformIT Ken, they were great!

      Regards,
      Jonas

      --- In scrumdevelopment@y..., "Ken Schwaber" <ken.schwaber@v...>
      wrote:
      > <Won't it be hard to create a stable architecture if you don't have
      > the end goal in sight? Or it is sufficient to use the information in
      > the backlog as a foundation?>
      >
      > Emergence of requirements and architecture, and self-organization
      are
      > research topics. Experientially, we know they work and are
      applicable to
      > software development, but the theoretical basis and its connection
      to
      > software development hasn't been made. See two articles that
      Prentice Hall
      > put up on www.informit.com under agile development that I wrote.
      >
      > <But doesn't it cause problems if highly skilled and
      > experienced engineers recieve the same salary as newly examined
      > nitwits? Are the Scrum team persistent? Do they remain the same in
      several
      > projects if they are well-fuinctioning?>
      >
      > In the overall performance review, evaluate the team and the
      individual's
      > contributions. Unless disfunction occurs, it's in the team and the
      > organization's benefit to keep teams working together, owning
      products and
      > systems.
      >
      > <Quite incompatible with the collective ownership rule of XP :-)>
      >
      > The product wasn't using XP, so we felt free to use this rule.


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    • Ken Schwaber
      Many methodologies initiate a project with a phase that defines the business architecture and the technical architecture of the system, in full. Based on the
      Message 2 of 11 , Nov 29, 2001
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        Many methodologies initiate a project with a phase that defines the business
        architecture and the technical architecture of the system, in full. Based on
        the user fully stated requirements, the team defines a model of the overall
        business processes and how they interact, as well as all of the technology
        that underlies the business processes and allows them to interact and
        operate with the reliability, scalability, and performance required. The
        problem with this approach is that the requirements have to be fully known
        to do so, and the implication is that the system will be delivered as
        modeled (either iteratively or with a big bang).

        Emergent architecture (business and technical) says that the team thinks
        through, designs, and builds only that architecture needed to support the
        business value (sprint goal) needed to deliver the functionality for that
        iteration (sprint). Anything beyond that architecture is speculative (since
        requirements emerge), unnecessary for supporting that sprint's
        functionality, and extra cost - both in development, debugging, and
        maintenance.

        Although the team may "whiteboard" an overall model of the the system prior
        to starting, so they have a context, the model only provides a context. The
        details emerge with each sprint.

        Ken

        -----Original Message-----
        From: Peter McGowan [mailto:peter@...]
        Sent: Thursday, November 29, 2001 10:28 AM
        To: Ken Schwaber
        Subject: Re: [scrumdevelopment] Re: book, "Agile Software Development
        with Scrum"


        Hi Ken,

        What's "Emerging Architecture"?

        Peter

        ----- Original Message -----
        From: "Ken Schwaber" <ken.schwaber@...>
        To: <scrumdevelopment@yahoogroups.com>
        Sent: Wednesday, November 28, 2001 7:34 PM
        Subject: RE: [scrumdevelopment] Re: book, "Agile Software Development with
        Scrum"


        > I don't understand the theoretical underpinnings of why emerging
        > architecture and design work either. A number of us that develop and
        > practice agile were talking about this the other day, and we agreed that:
        > 1. We don't know why it works.
        > 2. Preparing a detailed architecture and design at the beginning of a
        > project is wasteful. It presupposes the requirements, often leads to
        > developing technical capabilities that aren't needed (and require
        debugging
        > and maintenance), doesn't fit with the desire to simplify, and imposes
        costs
        > of the customer that they haven't agree to.
        > 3. In every case that we've relied on a stable architecture and design
        > emerging, they did. Part of the reason is refactoring, but I suspect that
        > the other reason has to do with team experience and the chaos theory
        > "strange attractor."
        >
        > So, this is another of my research areas.
        >
        > Ken
        >
        > -----Original Message-----
        > From: jonas.b@... [mailto:jonas.b@...]
        > Sent: Wednesday, November 28, 2001 6:03 PM
        > To: scrumdevelopment@yahoogroups.com
        > Subject: [scrumdevelopment] Re: book, "Agile Software Development with
        > Scrum"
        >
        >
        > Hi,
        > Emerging requirements and self-organization I can understand and
        > agree to. But I have harder understanding emerging architecture. Self-
        > organizing teams are just human nature, whereas architecture is a
        > complex composition which is hard to change. I don't imply that
        > emerging architecture is nonsense but I can't understand how it's
        > possible.
        >
        > Thanks for the articles on InformIT Ken, they were great!
        >
        > Regards,
        > Jonas
        >
        > --- In scrumdevelopment@y..., "Ken Schwaber" <ken.schwaber@v...>
        > wrote:
        > > <Won't it be hard to create a stable architecture if you don't have
        > > the end goal in sight? Or it is sufficient to use the information in
        > > the backlog as a foundation?>
        > >
        > > Emergence of requirements and architecture, and self-organization
        > are
        > > research topics. Experientially, we know they work and are
        > applicable to
        > > software development, but the theoretical basis and its connection
        > to
        > > software development hasn't been made. See two articles that
        > Prentice Hall
        > > put up on www.informit.com under agile development that I wrote.
        > >
        > > <But doesn't it cause problems if highly skilled and
        > > experienced engineers recieve the same salary as newly examined
        > > nitwits? Are the Scrum team persistent? Do they remain the same in
        > several
        > > projects if they are well-fuinctioning?>
        > >
        > > In the overall performance review, evaluate the team and the
        > individual's
        > > contributions. Unless disfunction occurs, it's in the team and the
        > > organization's benefit to keep teams working together, owning
        > products and
        > > systems.
        > >
        > > <Quite incompatible with the collective ownership rule of XP :-)>
        > >
        > > The product wasn't using XP, so we felt free to use this rule.
        >
        >
        > To Post a message, send it to: scrumdevelopment@...
        > To Unsubscribe, send a blank message to:
        > scrumdevelopment-unsubscribe@...
        >
        > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
        >
        >
        >
        > To Post a message, send it to: scrumdevelopment@...
        > To Unsubscribe, send a blank message to:
        scrumdevelopment-unsubscribe@...
        >
        > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
        >
        >
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