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

date start stop interrupt delta activity comments

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Time Log Entries Date Start - time in hours:minutes Stop - time in hours:minutes 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)