PSP Structure and scalability

PSP Structure

• PSP0: establish a performance baseline, make size, resource, and schedule plans
• PSP1: learn defect management and yield methods
• PSP2: scale up PSP methods to larger projects
• PSP3: master PSP skills and techniques

PSP0 Process Flow

• Requirements: problem description, PSP0 project plan summary form, time and defect recording logs, defect type standard, stop watch (optional)
• Process: planning, development, postmortem
• Planning: produce/obtain requirements statement, estimate development time, enter plan data, complete time log
• Development: design, implement, compile, test, fix defects, log defects and time
• Postmortem: complete project plan summary form, exit criteria: thoroughly tested program, completed project plan summary, defect and time logs

PSP Planning

• The PSP shows engineers how to estimate and plan their work
• Keys to making better estimates and plans: relevant historical data, statistically sound methods, defined estimating and planning process
• Engineers learn to make better estimates and plans with experience

Measurement in a Defined Process

• Measured historical data is needed for effective planning
• Measurement tells when and how process tasks are carried out
• Measured data is used to evaluate and improve a process
• The PSP uses three types of measures: effort, size, defects

Effort Measurement

• The PSP measures effort as time in minutes
• Time Recording Log is used to record time spent on each programming task, including interruptions
• Interruption time is recorded and subtracted from time spent on development tasks

Size Measurement

• Size data is used in estimating development time and expected number of defects
• Criteria for good size measures: correlation with effort, precise definition, can be counted automatically, suitable for planning, sensitive to language, design, and development method
• The PSP uses lines of code (LOC) for measuring size
• A physical LOC count is the number of non-blank, non-comment lines of source code
• A logical LOC count is related to a program's logical content, but depends on the programmer's definition of a logical line of code

Defect Measurement

• A PSP defect is an error made in a software artifact that must be changed
• Defects are classified according to a defect type standard
• For each defect, students record the defect type, description, and fix time
• All changes related to a single error are counted as one defect
• Fix time is recorded in the phase in which the defect is removed
• A Defect Recording Log is used for this purpose

Productivity and Costs of the PSP

• The PSP requires a time investment of about 1 to 2 hours per form and script
• Process updates will be needed at least every 3 months
• Data entry and analysis will take about an hour for each PSP-sized project
• The PSP also requires an emotional investment and a willingness to face personal limitations
• Software engineers have a clear view of their own limitations and must be able to face them

This quiz covers the PSP structure, establishing a performance baseline, making schedules, and scaling up PSP methods to larger projects. It also touches on team development.