📘 Software Sizing (Software Project Management)
🔹 1. Definition
Software sizing is the process of measuring the size of a software system to estimate effort, cost, time, and resources required for development.
👉 In simple words:
It tells us how big the software is, so we can estimate how much work it needs.
🔹 2. Purpose of Software Sizing
- Helps in project estimation
- Supports cost and effort prediction
- Improves planning and scheduling
- Helps compare different software projects
- Reduces project risk
🔹 3. Importance ⭐
- Basis of software estimation models (like COCOMO)
- Used for resource allocation
- Helps in productivity measurement
- Essential for project planning
🔹 4. Techniques of Software Sizing
🔸 1. Lines of Code (LOC) 📏
Measures software size based on number of written code lines.
🔹 Formula:
Size = Total number of executable lines of code
💡 Example:
- Small program = 1000 LOC
- Large system = 50,000 LOC
🔸 2. Function Point (FP) Analysis ⚙️
Measures size based on functionality delivered to the user.
🔹 Components:
- Inputs (EI)
- Outputs (EO)
- Queries (EQ)
- Internal Files (ILF)
- External Interfaces (EIF)
👉 Output = Function Points (FP)
🔸 3. Object Points 🧩
Used in object-oriented systems.
Measures:
- Screens
- Reports
- Components
👉 Each is assigned a weight and total size is calculated.
🔸 4. Use Case Points (UCP) 🎯
Based on use cases in system design.
Steps:
- Identify use cases
- Classify complexity
- Assign weights
- Calculate total points
🔹 5. Software Sizing Process
📌 Step-by-step:
🔹 Step 1: Break system into components (WBS)
🔹 Step 2: Identify sizing method (LOC, FP, etc.)
🔹 Step 3: Measure each component
🔹 Step 4: Sum all values
🔹 Step 5: Convert size into effort/cost
🔹 6. Diagram Description
📊 Software sizing flow:
Software System
↓
Decomposition (Modules)
↓
Size Measurement (LOC / FP / UCP)
↓
Total Size
↓
Effort & Cost Estimation
🔹 7. Types of Software Sizing
🔸 1. Absolute Sizing
- Based on actual measurable units (LOC, FP)
🔸 2. Relative Sizing
- Based on comparison with similar systems
🔹 8. Advantages of Software Sizing
✔ Helps in accurate estimation
✔ Supports planning and scheduling
✔ Improves project tracking
✔ Useful for cost prediction
✔ Helps compare project complexity
🔹 9. Limitations ❌
- LOC depends on programming language
- Early estimation may be difficult
- Function points need expert judgment
- Can be subjective in complex systems
🔹 10. Software Sizing vs Software Estimation
| Feature |
Software Sizing |
Software Estimation |
| Meaning |
Measures size |
Predicts effort/time |
| Output |
LOC / FP / UCP |
Cost, time, effort |
| Stage |
Early design |
Planning phase |
| Dependency |
Input for estimation |
Uses sizing results |
🔹 11. Important Exam Points
- Software sizing = measuring software size
- Methods: LOC, FP, Object Points, Use Case Points
- Used as input for estimation models
- Essential for COCOMO and project planning
🔹 12. Short Summary
- Software sizing measures how big a software system is
- Uses methods like LOC, Function Points, and Use Case Points
- It is the foundation for effort and cost estimation
🔹 13. Quick Exam Answer (2–3 lines)
Software sizing is the process of measuring the size of a software system using methods like Lines of Code, Function Points, and Use Case Points. It helps in estimating effort, cost, and time required for software development.
🔹 14. Likely Exam Questions
- Define software sizing.
- What are different software sizing techniques?
- Explain LOC method.
- What is Function Point Analysis?
- Why is software sizing important?
- Differentiate between software sizing and estimation.
- Draw software sizing process diagram.