05 Software Project Estimation and Scheduling Techniques

Software Project Estimation

Planning process for effort, duration, and cost.

Empirical Estimation Models

Models using formulas to predict project data.

Lines of Code Estimation

Counts total lines of source code in project.

E = (a + 4m + b)/6

Formula for estimating lines of code.

Cost Calculation

Cost equals estimated lines multiplied by cost per line.

Months Calculation

Months equals estimated lines divided by labor multiplier.

Maintenance Function

Function in payroll system with specific LOC estimates.

Transaction Function

Payroll function with defined LOC and cost.

Query Function

Payroll function estimating lines of code and cost.

Reports Function

Payroll function with specific LOC and cost.

Total Estimated LOC

Sum of lines of code across all functions.

Total Project Cost

Overall cost calculated for the entire project.

Total Estimated Effort Required

Total person-months needed for project completion.

Constructive Cost Model (COCOMO)

Estimates effort and cost based on program size.

Organic Mode

Simple projects with small teams and flexible requirements.

Semi-detached Mode

Intermediate projects with mixed experience teams.

Embedded Mode

Projects with strict hardware and software constraints.

Basic COCOMO Model

Model defining effort and time based on project type.

E = Ab (KLOC) Bb

Effort formula based on delivered lines of code.

D = Cb (E) Db

Development time formula based on effort.

Time Estimate (TE)

Estimated duration for completing each project activity.

Early Start Time (EST)

Earliest possible start time for an activity.

Late Start Time (LST)

Latest possible start time for an activity.

Float/Slack

Time an activity can be delayed without impact.

Critical Path

Sequence of activities that must be on schedule.

Critical Path Analysis

Determines start and finish dates for project activities.

Forward Pass Computation

Calculates earliest start time based on preceding activities.

Backward Pass Computation

Calculates latest start time based on succeeding activities.