Introduction to the Personal Software Process

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Introduction to the Personal Software Process

• Watts Humphrey
• Addison Wesley Longman c1997

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Humphrey on PSP

• a guide to using disciplined personal practices
  to do superior software engineering
• The PSP will show you how to plan and track your
  work and how to consistently produce high-quality
  software.

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Software Development

• Do you know how many lines of code you write per
  day? (or function points? or modules?)
• Do you know how many errors you make?
• Watts Humphrey knows how many LOC/day he writes
  and how many errors/KLOC he makes!

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Measurement

• Could a person train for running an olympic event
  without timing their performance?
• Would an archer train by shooting at a target but
  not seeing if the arrows hit the target?

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Time Log
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Time Log Entries

• Date
• Start - time in hoursminutes
• Stop - time in hoursminutes
• Interrupt - time of each interruption in minutes
• Delta - start - stop - interrupt
• Activity - category

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Engineering Notebook

• Record all activities related to class
• Post on web page update semi-weekly

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Class Discussion

• What can we learn from a programming time log?
• What are different uses of any knowledge gained
  from a time log?

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Possible Categories

• Drawing and revising object model
• Writing code
• Compiling and correcting syntax errors
• Testing code (no currently known errors)
• Debugging logic errors (that is, there is an
  error and you are trying to locate and correct
  the error - note)

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C2 time log

• This is a time log that I kept while design a
  programming problem and producing a solution
• My values

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Class Discussion

• Where my categories good?
• What would have been better categories?
• Any knowledge from this time log?

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Process Improvement

• 1. Measure
• 2. Evaluate
• 3. Modify
• Repeat steps 1-3

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Planning is essential

• You can estimate the effort required for your
  next project
• Accurate estimation comes only with practice.
• Estimate the next and then keep log to evaluate
  and improve estimates

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Personal Estimation

• The past is the best estimate of the future
• Find some size measure of the product
• e.g. loc, number of classes, number of functions
• determine your productivity based on size
• estimate size of next task
• calculate effort estimate

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Group Discussion

• How can we manage our time more effectively?
• How can we manage our team members time more
  effectively?
• How can we use PSP to improve our team members
  performance?

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Class Discussion

• What can we learn from a time log of our
  studying?
• What categories would be good for studying?

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L4aS17 time log

• Keep a time log of your class work for the next
  week 6/19 to 6/26
• Develop an extensive set of categories
• Summary including pie charts and productivity
• Turn in your log and an evaluation, summary on
  6/27 (on and off)