[Sharing] Key Software Project Metrics

Author: Trinh Hoang Long

Key Software Project Metrics Illustration

1. Technical Metrics

LOC (Lines of Code): Measures the total lines of source code. This can be either Physical LOC (counts blank lines and comments) or Logical LOC (counts only executable statements).
- A large unit (1 KLOC = 1,000 LOC).
- Measures lines of code, reflects project size.
Cyclomatic Complexity: Measures code complexity by counting the number of independent paths in the code. More complex code is harder to test and maintain.
Code Coverage: The percentage of code executed by tests (unit tests, integration tests). Higher coverage usually means better quality.
Defect Density: Number of bugs found per unit of size, as well as the number of bugs that escape each testing stage—reflects test effectiveness.
Formula:
```
Defect Density = Number of bugs found / Software Size (e.g., KLOC)
```

2. QA Metrics

Test Coverage: Percentage of code executed by tests (unit tests, integration tests). Higher coverage indicates higher quality.
Testing Effort & Budget: Time, effort, and costs spent on testing.
Bug Detection: Average time to discover a bug.
Test Execution: Number of test cases executed in a time frame.

3. Productivity Metrics

Lead Time: Time from receiving a requirement to delivering the finished product.
Deployment Frequency: Frequency of software releases.
Change Failure: Percentage of failed changes after deployment.
Time to Repair: Average time to fix a bug once detected.
On-Time Delivery: Percentage of features/products completed on schedule.
Resource Utilization: The time team members spend on main tasks (excluding meetings, admin, etc.).
Velocity in Scrum/Agile: Total story points completed per sprint. Important for estimating future sprints.

4. Project KPIs

Scope Change: Degree of project scope changes.
Commitment & Delivery: Ratio of committed story points vs. actually completed story points in agile projects.
Cost Variance: Difference between actual spend and estimated budget for completed work.
Milestone: Level of compliance with critical milestones.
Customer Satisfaction: Measures satisfaction of customers and end users with the product.
Team Satisfaction: Measured via surveys or periodic meetings—like sprint planning, retros, daily standups, etc.

More about KLOC

1. What is KLOC?

KLOC stands for Kilo Lines of Code, that is, One Thousand Lines of Source Code.

Kilo: Means 1,000.
LOC (Lines of Code): Number of source code lines in a program.

In other words, 1 KLOC = 1,000 lines of code.

This metric is mainly used to measure the size of a software project.

2. KLOC’s Role in Project Management

Cost Estimation: often uses the formula: Total Cost = (Expected KLOC) x (Average cost to produce 1 KLOC)
Productivity Measure: Calculate developer or team productivity as: LOC/day or LOC/month
Quality Assessment: Calculate defect density using: Number of bugs / 1 KLOC

3. KLOC: Problems and Limitations

Although a simple measure, KLOC is controversial because of the following limitations:

A. Improper measurement of LOC

Programming languages: A feature may need 100 LOC in C++, but only 20 LOC in Python or Ruby. Comparing KLOC across languages is meaningless.
Verbose code: Focusing on code line count may encourage developers to write unnecessarily long, unoptimized, and non-reusable code just to increase LOC.

B. Does not measure Quality

Code quality: A developer writing 100 high-quality LOC is more valuable than someone writing 1,000 buggy or hard-to-maintain LOC.
Code reuse: If a developer reuses a library and writes only 10 LOC, that is high productivity (reduced time), but the KLOC metric seems low for them.

C. Misleading for Productivity

Suppose a developer removes 500 unnecessary lines, cleaning up the project and improving efficiency. If we use KLOC, his productivity is -0.5 KLOC, which doesn’t reflect the work’s true value.

4. Conclusion & Advice 💡

KLOC is still a basic indicator to make rough estimates of large codebases’ size.

Advice: Never use KLOC as the sole measure to evaluate performance, salary, or reward people or teams.

Instead, focus on metrics that bring real business value, such as:

Velocity (agile): measuring story points per sprint.
Completion time: the time from starting a task to delivering it to users.
Defect rate: number of real-world bugs found in production.

Thanks for reading! If you have any questions, let’s discuss!