Software measurement and metrics are crucial aspects of software development, providing valuable insights into the size, quality, and productivity of the development process. Size-oriented metrics are a specific category of software metrics that use the size of the software as a baseline for normalization. Here’s an overview of various size-oriented measures:
Lines of Code (LOC):
- Description:Â The most common size-oriented metric, LOC simply counts the number of lines of code in the program.
- Limitations:Â LOC can be misleading as it doesn’t consider the complexity of the code or the programming language used. A program with fewer lines of complex code written in a low-level language can be more challenging to understand and maintain than one with more lines of simpler code written in a high-level language.
Function Points (FP):
- Description:Â Function points are a more holistic measure that considers the functionality delivered by the software rather than just lines of code. It takes into account five main factors:
- Inputs: The number of external inputs provided to the system.
- Outputs: The number of external outputs generated by the system.
- Inquiries: The number of times users interact with the system to retrieve data.
- Internal Logical Files (ILFs): The number of data entities stored within the system.
- External Interface Files (EIFs): The number of interfaces with external systems.
- Benefits:Â Function points provide a language-independent measure of software size, making it easier to compare projects written in different languages.
Other Size-Oriented Measures:
- Non-commented Source Lines of Code (NCSLOC):Â Similar to LOC but excludes comments and blank lines.
- Delivered Source Lines of Code (DSLOC):Â Focuses on the code delivered to the customer, excluding internal development code.
- Equivalent Lines of Code (ELOC):Â Estimates the amount of code in a specific language that would be functionally equivalent to the existing code in another language.
Using Size-oriented Metrics:
These metrics are valuable when used alongside other software quality and productivity metrics. Here are some common applications:
- Effort Estimation:Â Historical data on LOC or function points can be used to estimate the effort required for future projects of similar size.
- Project Planning:Â Size metrics can aid in project planning by providing a baseline for scheduling and resource allocation.
- Productivity Measurement:Â Metrics like LOC per developer-month can be used to assess developer productivity, but should be interpreted with caution considering the limitations of LOC.
- Quality Control:Â Trends in size metrics can be monitored to identify potential quality issues, such as code complexity.
Important Considerations:
- Size-oriented metrics alone don’t provide a complete picture of software quality or development effectiveness. They should be used in conjunction with other relevant metrics.
- The chosen metric (LOC, function points, etc.) should be appropriate for the project and development methodology.
- It’s essential to avoid focusing solely on maximizing code production based on size metrics, as this can lead to sacrificing code quality and maintainability.
By effectively utilizing size-oriented metrics along with other measurement practices, software development teams can gain valuable insights to improve project planning, resource allocation, and overall software quality.