Personal Software Process

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Personal Software Process

• CS4320
• Fall 2002

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Agenda

• Watts Movie
• Intro to PSP

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PSP

• PSP 0 Baseline Process
• PSP 1 Personal Planning Process
• PSP 2 Personal Quality Management
• PSP 3 Cyclic Personal Process

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Rationale

• Understanding thru measurement and tracking
• Defined process based on experience
• Select appropriate methods using data
• Structure enhances teamwork, improves efficiency

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(No Transcript)
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Baseline Process

• Uses scripts 0 and 0.1
• Tracks Time by phase and interruption
• Tracks Defects by category, type, time to fix
• Time in minutes (rounded to whole, neverlt1)
• Phases of project
• Design, Code, Compile, Test
• Simple project plan, estimate development time,
  actuals on everything else
• 0.1 adds code size estimates, Base, Deleted,
  Modified, Added, Reused

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Code Metrics

• (B)Basethe LOC of the code (prev version)
  before project starts
• (D)Deletedthe LOC of the prev version that were
  deleted as not applicable to new project
• (M)Modifiedthe LOC of the prev version that were
  modified for the new project
• (A)Addedthe LOC that you created new for this
  project
• (R)Reusedthe LOC that were reused from other
  projects
• (N)Total NewChangedAddedModified
• (T)Total LOCThe LOC of the final project code
• Checks
• NAM
• A(T-(B-D)-R)

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What gets counted?

• Code Counting Standard
• Varies by language
• Blank lines?
• Comments?
• Compound Statements?
• BE CONSISTENT!!!
• Normally Logical Lines of Code

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PSP 1 Code Size Estimation

• Wideband-Delphi
• Group of Experts estimate tasks, assign times
• Facilitator tries to get convergence
• Divergence generates discussion of issues
• More accurate results achieved
• Fuzzy-Logic
• Compare to historical projects
• Requires large database

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PSP Probe Method

• PROxy-Based Estimating
• For example Homebuilding sq ft estimates
• Uses objects as proxies for the estimation effort
• Steps
• Determine Conceptual Design
• Estimate Object Type and Size
• Estimate Method count
• Use calculation tables
• Table C39

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Factor Tables for PSP
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NOT More Statistics!!!!

• Xavg average of estimates
• Yavg average of actual sizes
• Estimating Linear Progression Parameters
• ß0 Yavg ß1 Xavg
• ß1 sum(xiyi) nxavgyavg
• Range Get a calculator!!!!!
• Need 3 data points to get started

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PSP 1.1

• Adds time estimation to size estimation, adds EV
• Compute available hours, Total utilization
  factor
• Determine tasks and record on Table 6.11 Schedule
  Planning Template
• Break out available project time by week
• Plan the task sequence
• Set task schedule
• Establish milestones

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Earned Value

• Assign a value to each task
• Credit that value when the task is done
• Each task is estimated by time
• It EV is equal to its percent effort
• A 1000 hour project with a 15 hour task, that
  task has an EV 1.5
• Partially completed tasks get 0
• A solution to status tracking problem

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PSP 2

• Adds Design and Code Reviews
• Follow checklist for reviews
• Informal
• Individual
• PSP says review BEFORE compile
• Yield defects before compile/ defect after
  compile

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PSP 2.1

• Adds design templates
• Operational Scenario Template (C66)
• Describes operational behavior of program
• Functional Specification (C68)
• Define Class interfaces for public methods
• State Specification (C70)
• Define states and transitions
• Logic Specification (C72)
• Pseudo-code for critical modules

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PSP 3

• Cyclic Development (Staged Delivery)
• Adds High-Level Design
• Bug Tracking Log

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Next

• So how do groups do this stuff?
• TSP Team Software Process