The Primary Software Testing Metrics

Bangalore: A Software metric aims at measuring a particular property of the software or its specifications. Metrics are an important factor to be considered for the Test Team. They allow deep understanding of the performance of an application and how it behaves. The fine tuning of the application can be improved only with knowledge of metrics. In a typical Quality Assurance process, there are many metrics which can provide useful information. Take a look at a few important among them:

Function Test Coverage Metric- This could be used to measure test coverage before software delivery. It gives the percentage of the software that has been tested at any point during testing.

Software Release Metrics: You can state that a software is ready for release when it has been tested with a test suite that provides 100% functional coverage, 80% branch coverage, and 100% procedure coverage. The defect finding rate should also ideally be less than 40 new defects per 1000 hours of testing.

Software Maturity Metric: This could be used to determine if a software system is ready to be released. This index is particularly helpful for assessing release readiness when several modifications are made to existing software systems. It also provides a historical index of the impact of changes, additions or deletions that have been made.

Reliability Metrics: Reliability can be defined using the below relation:

Reliability = 1 – Number of errors (actual or predicted)/Total number of lines of executable code
This value is calculated for the number of errors during a specified time interval. Three other metrics can be measured during extended testing or after the system is in production. They are:

MTTFF (Mean Time to First Failure)‏
MTTFF is the number of time intervals for which the system has been operable until it experiences its first failure (functional failure only).

MTBF (Mean Time Between Failures)‏
MTBF is measured as the sum of the time intervals for which the system is operable.

MTTR (Mean Time To Repair)
MTTR can be defined as the sum of the time intervals required to repair the system.