Inspection Metrics in Software Engineering

Inspection metrics in software engineering measure the effectiveness of code reviews, design reviews, and other forms of inspections in identifying and resolving faults in the software. These metrics can help measure the efficiency and quality of the inspection process and provide insights into areas for improvement. Some common inspection metrics include:

1. Defect density: This metric measures the number of defects per unit of code. It is calculated by dividing the total number of defects found during an inspection by the total number of lines of code inspected.
2. Inspection rate: This metric measures the speed at which code is being inspected. It is calculated by dividing the total number of lines of code inspected by the total time taken to complete the inspection.
3. Defect discovery rate: This metric measures the rate at which defects are discovered during an inspection. It is calculated by dividing the number of defects found during an inspection by the total number of lines of code inspected.
4. Defect removal efficiency: This metric measures the percentage of defects that are removed during an inspection. It is calculated by dividing the number of defects removed during an inspection by the total number of defects found during the inspection.
5. Inspection participation rate: This metric measures the percentage of team members who participated in the inspection. It is calculated by dividing the number of team members who participated in the inspection by the total number of team members.
6. Inspection coverage rate: This metric measures the percentage of code that was inspected during an inspection. It is calculated by dividing the total number of lines of code inspected by the total number of lines of code in the system.
7. Review effort: This measure counts the amount of time and labor used in the inspection procedure. It assists in determining prospective areas for process improvement and assessing the cost-effectiveness of inspections.
8. Defect repair time: It gauges how long it takes to address and correct flaws found during the inspection procedure. This statistic aids in organizing follow-up development efforts and offers insights into how well the problem resolution process is working.
9. Reviewer effectiveness: It is a statistic that assesses each reviewer’s performance individually based on standards like the quantity of faults discovered, review coverage, and review guidelines fulfilment. It assists in identifying competent reviewers and areas that could need more training.

These metrics can be used in combination to provide a comprehensive view of the inspection process and to identify areas for improvement. It’s important to note that, these metrics should be tracked over time to identify trends and patterns, which can help identify areas for improvement.

Monitoring inspection process is very essential and important to simply get early estimate of software’s quality, assess staff’s conformance to inspection procedures, and identify status of inspection process. Metrics generally provide subjective assessment of total number of faults or defects that are remaining in code after inspection. Inspection quality status is basically long-term metric of company’s or division’s being accumulated inspection experience. Inspection quality status will usually depict characteristics of inspection in long term when software quality and inspection raw data explain and define the status of particular inspection. Data that is usually collected during software process is simply required to compute set of metrics. These metrics support evaluation and improvement of process along with quality of planning and tracking. Metric that is computed during such process must be explained and defined by requirements of organization that too in quality manual. Collection of data and calculation of metrics for no reason is simply considered as waste of time. Inspection quality status is generally composed of two different types of metrics i.e.

• Average Quality Metrics : It can be characterized in terms of time used, number of inspectors that are participating, and number of defects that are being detected.
• Maturity Metrics : It describes extent of inspection adoption. It is also new metric.

During Inspection Process, there are several metrics that can be calculated. Some of them are given below :

1. Total number of major and minor defects being found : It is usually found by reviewer.
2. Number of major defects that are found to total found : It proportion of minor defects to major defects is much greater, then moderator might request to reviewer to repeat review and focus on major defects much prior to commencing logging meeting.
3. Size of the artifact : It can be pages, LOC, or other size measures.
4. Rate of review : It represents size of reviewed artifact that is divided by time i.e. expressed in hours. Example, 14 pages/hour.
5. Defect detection rate : It represents total number of major defects that are found per review hour.

Number of Defects Found and Defects Density :

1. Number of Defects : Total number of defects that are found is sum of total number of defects that are found by every reviewer, minus number of defects found that are common. For example, consider instance, for two reviewers, metric is computed by :
2. Defect Density : It is the ratio of total number of defects found to size of artifact. In simple words, it is defined as total number of confirmed defects that are detected in software during period of development, divided by size of software. It simply helps us to decide whether or not piece of software is ready to be released. It also allows us to compare relative number of defects in various software components that further helps in finding candidates for additional testing or inspection. It is expressed as :

ADVANTAGES OR DISADVANTAGES :

Advantages of using inspection metrics in software engineering include:

1. Improved quality: By tracking and analyzing inspection metrics, developers and managers can identify areas where the software has a high number of defects and take steps to improve the quality of the code.
2. Increased efficiency: Inspection metrics can help identify areas where the inspection process is slow and take steps to speed it up.
3. Better decision making: Inspection metrics can provide managers and team leaders with valuable data that can be used to make informed decisions about the inspection process and identify areas for improvement.
4. Increased accountability: Inspection metrics can help hold developers and teams accountable for the quality of their code.
5. Improved team communication: Inspection metrics can help team members understand their role in the inspection process and how they can contribute to improving the quality of the code.
6.  By identifying and resolving defects early in the development process, inspection metrics can help reduce the costs of rework and delays later in the project.

However, there are also some disadvantages of using inspection metrics in software engineering:

1. Complexity: Collecting and analyzing inspection metrics can be complex, especially for large and complex systems.
2. Time-consuming: Collecting and analyzing inspection metrics can take a lot of time, which can lead to delays in the project schedule and increased costs.
3. Not always accurate: Inspection metrics may not always be accurate and may not provide a complete picture of the inspection process.
4. Dependence on human interpretation: Inspection metrics are often dependent on human interpretation, which can lead to inconsistencies and errors.

Overall, inspection metrics can provide valuable insights into the effectiveness of the inspection process and help identify areas for improvement. However, it is important to use them in combination with other metrics and to be aware of their limitations to make the best use of them.