No Silver Bullet - Essence and Accident in Software Engineering

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No Silver Bullet - Essence and Accident in
Software Engineering

• By R. Adam Mead

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Software Construction Essential Tasks

• Exploiting the mass market to avoid constructing
  what can be bought.
• Using rapid prototyping as part of a planned
  iteration in establishing software requirements.
• Growing Software organically, adding more and
  more function to systems as they are run, used
  and tested.
• Identifying and developing the great conceptual
  designers of the rising generation.

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Does It Have to Be Hard? - Essential Difficulties

• Observe that it is not software process that are
  so slow it is that hardware progress are so fast.
• The essence of a software entity is a construct
  of interlocking concepts data sets,
  relationships among data items, algorithms, and
  invocations of functions.

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Complexity

• Software is more complex for their size then an
  others human construction.
• Many problems of developing software products
  derive from this essential complexity and its
  nonlinear increases with size.
• The increase in size makes communication among
  team members hard.
• Problem are product flaws, cost overruns,
  schedule delays.
• Are not only technical problems, management
  problems too.

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Conformity

• Conformity comes from the fact that all new
  software must conform to the way things where
  done in the past, because it is hard to change
  everyone.
• Main reason software must conform is that it is
  new on the scene.

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Changeability

• Being able to change something after it has been
  constructed is a new concept.
• Software must be able to change, and the
  complexity of the systems becomes harder to
  follow.
• All successful software gets changed.
• Successful software also survives beyond the
  normal life of the machine vehicle for which it
  is first written for.

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Invisibility

• Software has no 3-D way on which it can be laid
  out.
• Software does not have one map or graph, it will
  have multiple maps and graphs.
• Software has data flow charts, time sequence
  graphs, and other types of things.
• Communication becomes hard because each person my
  see it a different way.

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Past Breakthroughs Solved Accidental Difficulties

• High-Level Languages
• Time-Sharing

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High-level Languages

• The most powerful thing to happen to software
  development ever.
• It allows that some types on data structures,
  operation, classes etc, to be used by any
  machine.
• Programmers dont have to develop software for
  individual machines.

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Time-Sharing

• Most observers credit the time-sharing
  improvement to better programmers, and better
  programming languages.
• Programs run faster because of the high-level
  languages.
• Do not have to accommodate for machine language
  anymore.

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Hopes for the Silver

• Object-oriented programming
• Artificial Intelligence
• Expert Systems
• Automatic programming
• Graphics programming