Metrics in software development

Metric is a measurement used to compare two or more products,processes,or projects.
Software metrics help in-

• Estimation of size and complexity of project
• Tracking the progress of project
• Analyzing the effectiveness of software progress and taking corrective action if necessary.
• Measuring productivity of people.

1. Person Month Metric - The effort required for execution of project is measured in person months(PMs).
e.g.-If a person works for a month,effort is 1 PM.

2. Product Metrics - To estimating the size of project is very difficult task.One accepted method of estimating product size is using the metric KDSI(Kilo or Thousand delivered source instructions) or KLOC(Kilo Lines of code).
Based on KDSI,a project can be categorized as small,intermediate,medium,large or very large.

3. Productivity Metrics - The number of lines that can be written by a programmer in one hour can be used as a metric for measuring the productivity of programmer i.e. the Delivered Source Instructions (DSI) per hour.
Another metric used for productivity is the number of defects removed per hour by programmer.

4. Quality Metrics - To measure the quality of product,following metrics can be used -

• Number of defects found per KDSI(Known as defect density)
• Number of chages requested by customer after software is delivered.
• MTBF(Mean Rime Between Failures) i.e. average time between failures.
• MTTR(Mean Time To Repair) i.e. average time required to remove a defect after it is detected.