Quote%20of%20the%20Day

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Quote of the Day

• The programmer, like the poet, works only
  slightly removed from pure thought-stuff. He
  builds his castles in the air, from air, creating
  by exertion of the imagination.
• Frederick Brooks Mythical Man Month, 1995

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PERT Diagrams

• Program Evaluation and Review Technique

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Critical Path

• If there are N tasks with dependencies between
  the tasks, what set of tasks determines the
  minimum completion time for the whole project?
• This is the critical path.

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Critical Path Algorithm (part 1)

• For each node (until completion time of all
  nodes are calculated)
• if the predecessors are completed, then take
  latest completions time and add required time for
  this node
• this is the completion time.
• The node with the latest completion time
  determines the earliest completion time for
  project.

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Example
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Critical Path Algorithm (part 2)

• Starting with the node with latest completion
  time, mark it as critical.
• Select predecessor node with latest completion
  time, mark it as critical.
• Continue until reaching start node.

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Example
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Critical Path Algorithm (part 3)

• Slack time is the amount of time that a specific
  task can be delayed without changing the project
  delivery time
• For each noncritical node starting with the last
  node, determine the earliest of the latest start
  times of the successor nodes. This is the latest
  completion time. Make the latest start time for
  the node to reflect this time.

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Example
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TTYP
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Terms

• Outsourcing/Off shoring
• Software crisis
• Prototype
• Capability Maturity Model

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Goals

• Know concepts of SLC
• Know differences in SLC Models
• Be able to choose a SLC Model
• Be able to understand and specify a software
  process using actor-artifact-action model

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Software Crisis

• Software is delivered over-budget, late, and not
  correct
• software complexity
• programmer productivity
• DeMarcos (IEEE Software Apr 94)
• only too costly because they would like to pay
  less
• only late because they want it sooner

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Future of Software

• increasing complexity
• increasing criticality

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How to achieve quality

• Top-down
• through software life cycle
• through quality improvement
• see Dilbert
• Bottom-up
• Personal Software Process

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Software Life Cycle (SLC)

• formalizing the process of
• software development
• Pressman20-70

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TTYP - SLC Models
Prototyping
RAD
Incremental
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SLC Models working versions
End of development
Middle of development
End of first cycle
Start of development
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SLC Models req completion
End of development
Middle of development
End of first cycle
Start of development
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SLC Models advantages
waterfall
prototyping
RAD
Incremental
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Software Process

• a process model depicts the tasks that are done
  to achieve software development
• process models usually depict
• Actions (Tasks)
• Artifacts (files,data,etc)
• Actors
• decisions (optional)

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Process Segment
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Purpose of Process Models

• Understanding of what is (should be) done
• training
• management
• Automation
• clerical
• analysis

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Assignment

• Thursday, Sep 28
• Review for exam
• Tuesday, Oct 3
• Exam 1