Size Estimation

Commonly used metric for software size estimation

• Source lines of code (SLOC)

• Function Points (FP)

  • Based on Requirement specs

• Use case points (UCP)

  • Based on Use Cases

Source Lines of Code (SLOC)

There are two types of SLOC:

• Physicial SLOC: Count excluding comments and blank lines.

• Logical SLOC: Measure the number of executable "statements", but their specific definitions are tied to specific computer languages.

Advantages of SLOC

• Scope for Automation of counting: since lines of code is a physical entity it is easy to count and can be automated using a tool.

• An intuitive metric: Lines of code serves as an intuitive metric for measuring the size of software because it can be seen and the effect of it can be visualized.

Disadvantages of SLOC

• Variability: depends on programmer experience, language, framework support, reuse etc.

• It is difficult to estimate the number of lines of code that will be needed to develop a system from information that is available in analysis and design phases

• Lack of universally accepted definition for exactly what a line of code is.