Which Software Metrics to Choose, and Why?

Software development metrics enable developers to track and understand progress, identify problems and obstacles, fine-tune strategies, and set realistic goals. To make the most of them, it’s crucial to pick the right metrics for your team’s particular needs.

Selecting the appropriate metrics can be daunting. There are many different types of metrics, each promising different value-added opportunities for your specific project.

This article aims to identify qualities to look for in software metric approaches and provide examples of metrics you should consider for your next project. You’ll also find tips for improving your development strategy as you put those metrics to work.

What are software metrics, and why are they important?

Software metrics are measurements used to evaluate the effectiveness of a software development process and the software itself. For example, they can measure a software application's performance and quality by calculating system speed, scalability, usability, defects, code coverage, and maintainability.

Metrics can provide invaluable data that allow software developers to identify issues early on and make necessary corrections before too much damage is done. They also help them stay on track with project estimates and deadlines.

Additionally, software metrics offer insight into potential conflicts between developers and stakeholders. These metrics are essential for ensuring that a program meets the customer or client’s expectations and can help teams make decisions that will best serve the interests of all parties involved.

Recommended reading: Managing Complex Digital Transformation Programs

Software Metric Categories & Metric Examples

There are numerous metrics that developers can focus on when creating and maintaining a software program. To simplify things, here are four ways developers can categorize metrics.

The first category of software metrics that software developers should consider is performance. Performance metrics measure the speed, reliability, and scalability of a system. Examples include response time, throughput, resource utilization, and memory usage. These metrics are essential for understanding how well a system handles requests.

The second category developers could use is quality. Quality metrics measure the correctness and completeness of a system and can include code coverage, defect density, and test case pass rate. These metrics are crucial for understanding how well a system performs in terms of its ability to produce correct results and meet customer requirements.

Usability is another important metric category to consider. Usability metrics measure the ease of use of a system. Usability metrics include user satisfaction scores, task completion time, and error rate. These metrics are important for understanding how well a system performs in terms of its ability to be used by customers.

Finally, the fourth category is maintainability. Maintainability metrics measure the ease of maintenance and modification of a system. Examples include code complexity, technical debt, and refactoring rate. These metrics are vital for understanding how well a system performs regarding its ability to be maintained and modified over time.

Which metrics software developers look at will depend on the goals, requirements, and constraints of the stakeholders and development team. Now that we’ve looked at different metric categories developers can consider, it’s time to look at a few specific metrics.

Other Software Metrics to Consider

1. True Test Coverage measures the amount of tested code. It’s the percentage of code lines, branches, and states verified during unit tests. True test coverage shows which parts of an application are well-tested and which need further testing. By regularly measuring true test coverage, developers can improve the quality assurance process and ensure defects are detected before a software’s release.
2. Team Velocity is a software development practice that measures how much work a team completes in an iteration. It's conveyed in story points per iteration, and it serves as a way to measure how quickly the team is working on a project. Velocity helps keep teams motivated and focused on completing their goals within each iteration, incentivizing them to continue their efforts. It also provides valuable data for resource planning and estimations of future sprints.
3. Escaped Defects are issues that emerge during the software development process and make it into the released version of the application, despite having been missed during testing. These problems can happen when the development team needs more strategies to thoroughly test all features and issues before releasing a version. Escaped defects cause severe problems down the line and often result in costly rework, customer dissatisfaction, and lost time.
4. Release Burndown is a project management tool used to track the progress of long-term projects. The goal is to accurately predict and manage changes in scope and timeline to meet successful delivery dates. It provides visibility over project features, tasks, goals, and performance metrics in a graphical burndown chart form and a tabular spreadsheet format. In addition, release burndown can help identify bottlenecks or delays.
5.  Lead Time is the period of time between the beginning of a project and its delivery. Lead times can vary greatly depending on the specific project but typically encompass several activities that must be completed before the software is ready.
6. Customer Satisfaction measures customers’ happiness with a product or service. Customers are satisfied when the software’s performance has met or exceeded their expectations. Measuring customer satisfaction is important because it allows businesses to identify weak points in their service and address them quickly.
7. The Open/Close Rate for software development is the number of tasks within a given period that are in process versus the number completed. It’s usually calculated as the percentage of total opened to closed tickets on a daily, monthly, or yearly basis. This metric helps organizations understand how quickly their development team can complete tasks and accommodate fluctuating demands from different stakeholders.
8. The Defect Detection Percentage (DDP) is a metric used to measure the proportion of coding errors identified during software development and testing. It is an important metric used to evaluate the success rate of a project. A higher DDP indicates better quality assurance and reduces future maintenance costs.

Recommended reading: Continuous Inspection: How to Define, Measure and Continuously Improve Code Quality

The Goal Question Metric Approach

Basili’s Goal Question Metric (GQM) is a metric evaluation approach developers often use for its clear structure and ease of use. The GQM is a software quality analysis technique that defines and measures software development, maintenance, and improvement objectives.

It enables project teams to analyze their achievements and problems regarding productivity, schedule, cost, or quality. The GQM is broken up into a three-step analysis process: defining the goals, the questions, and the metrics. Here’s an explanation of how to utilize the GQM approach by its founder:

“A GQM model is a hierarchical structure… starting with a goal (specifying purpose of measurement, object to be measured, issue to be measured, and viewpoint from which the measure is taken). The goal is refined into several questions, such as the one in the example, that usually break down the issue into its major components. Each question is then refined into metrics, some of them objective such as the one in the example, some of them subjective…

The same metric can be used to answer different questions under the same goal. Several GQM models can also have questions and metrics in common, ensuring that, when the measure is actually taken, the different viewpoints are taken into account correctly (i.e., the metric might have different values when taken from different viewpoints).”

The GQM approach is an excellent choice for software metric selection and analysis because it focuses on the project’s goals and provides a way to measure progress. Additionally, it allows developers to track progress over time and make adjustments as needed.

Final Takeaways

When choosing software metrics, it’s important to consider your project's specific needs and select metrics relevant to them.

Performance, quality, usability, and maintainability metrics should all be considered so you have a comprehensive understanding of how well your system is performing.

By selecting the right metrics for your software development project, your team can gain valuable insights into the progress of their development efforts and make informed decisions about how to improve them.

More helpful resources:

• Managing Complex Digital Transformation Programs [Whitepaper]
• Next-Generation Architecture Best Practices [Blog]
• Best practices for selecting a software engineering partner [Whitepaper]