📘 Project Metrics & Software Project Estimation

(Software Project Management – Exam Notes)

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🔹 1. Project Metrics

🔸 Definition

Project metrics are quantitative measures used to evaluate, monitor, and control software project performance.

👉 In simple words: They are numbers that tell how well the project is performing.

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🔸 Purpose of Project Metrics

• Measure project progress
• Improve productivity
• Track cost and time performance
• Ensure software quality
• Support decision-making

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🔸 Types of Project Metrics

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🔹 1. Size-Oriented Metrics 📏

Measure software size in terms of lines of code (LOC).

Example Metrics:

• LOC (Lines of Code)
• Cost per LOC

Formula:

Productivity = LOC / Effort

👉 Example: 1000 LOC / 10 person-days = 100 LOC/day

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🔹 2. Function-Oriented Metrics ⚙️

Measure software based on functionality delivered.

Key Metric:

• Function Points (FP)

👉 Focus:

• Inputs
• Outputs
• Files
• Queries
• Interfaces

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🔹 3. Productivity Metrics 🚀

Measure output per unit effort.

Formula:

Productivity = Output / Effort

👉 Example:

• 2000 LOC / 20 days = 100 LOC/day

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🔹 4. Quality Metrics ⭐

Measure software quality.

Examples:

• Defect density
• Error rate
• Customer satisfaction

Formula:

Defect Density = Number of Defects / Size of Software

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🔹 5. Cost Metrics 💰

Measure project cost efficiency.

Example:

• Cost per function point
• Cost per LOC

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🔹 2. Software Project Estimation

🔸 Definition

Software project estimation is the process of predicting effort, cost, time, and resources required to complete a software project.

👉 In simple words: It answers: “How much time, money, and effort will the project need?”

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🔸 What is Estimated?

• ⏱ Effort (person-days/months)
• 📅 Time (duration)
• 💰 Cost (budget)
• 👨‍💻 Resources (team size)

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🔸 Importance of Estimation

• Helps in project planning
• Prevents cost overruns
• Ensures realistic deadlines
• Improves resource allocation
• Reduces project failure risk

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🔹 3. Techniques of Software Estimation

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🔸 1. Expert Judgment 👨‍💼

• Based on experience of experts
• Fast but subjective

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🔸 2. Analogous Estimation 📊

• Uses similar past projects

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🔸 3. Parametric Estimation 📐

• Uses mathematical formulas

Example:

Effort = Size / Productivity

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🔸 4. COCOMO Model ⭐ (Important)

COCOMO Model is a popular algorithmic model for estimating effort and cost.

Basic Idea:

Effort = a × (KLOC)^b

👉 Where:

• KLOC = Thousand Lines of Code
• a, b = constants depending on project type

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🔸 5. Three-Point Estimation (PERT) 🎯

Uses:

• Optimistic (O)
• Most Likely (M)
• Pessimistic (P)

Formula:

TE = (O + 4M + P) / 6

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🔹 4. Relationship Between Metrics & Estimation

• Metrics provide historical data
• Estimation uses this data to predict future effort
• Better metrics → more accurate estimation

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🔹 5. Key Differences

Feature	Project Metrics	Project Estimation
Meaning	Measurement of performance	Prediction of effort/time
Type	Actual data	Future prediction
Use	Monitoring	Planning
Example	Defect rate	Project cost

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🔹 6. Important Exam Points

• Metrics = measure performance
• Estimation = predict project requirements
• Estimation depends on metrics + experience
• COCOMO is a widely used estimation model
• Both are essential for successful project management

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🔹 7. Short Summary

• Project metrics measure software performance (cost, quality, productivity).
• Software estimation predicts effort, cost, and time.
• Both are essential for planning, controlling, and delivering successful software projects.

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🔹 8. Quick Exam Answer (2–3 lines)

Project metrics are quantitative measures used to evaluate software performance, while software project estimation is the process of predicting effort, time, and cost required for project completion. Both help in effective planning and control of software projects.

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🔹 9. Likely Exam Questions

1. Define project metrics.
2. What is software project estimation?
3. Differentiate between metrics and estimation.
4. Explain types of software metrics.
5. What is COCOMO model?
6. Write formula for PERT estimation.
7. Why is estimation important in software projects?