Software Test Metrics ◾ 121
useful feedback to the test management. e test team would strive to fill in the
gaps in these areas. e first refers to quality test cases. e second pertains to a
commitment to execute test case.
Test Coverage
Functionality Coverage
It is vital to know the proportion of requirements (functionalities) covered by test
cases. is is the simple and most widely used test coverage metric. is metric
helps to control and improve coverage and makes the application more usable by
customers. As testing is in progress, coverage will increase in the light of this metric
and will reach 100% in the ideal case.
Code Coverage
Yet another coverage metric traces the proportion of code covered by test cases.
Coverage helps eliminate gaps in a test suite.
is is a tenuous metric. Higher coverage does not mean assurance of better
quality. An experienced tester knows to take a balanced view on this and make sure
a minimum coverage has been achieved and critical paths have been covered.
Code coverage is a very useful metric.
However, you need to know how to use it.
Coverage metric tools are available to track line, statement, block, decision,
path, and condition coverage. ey provide excellent reports with back tracing and
help achieve higher test efficiency.
Box 8.3 uniT TeST DefeCT DaTa
A unit test is cost effective. It improves reliability. It reveals bugs that are
otherwise devious. A unit test needs design knowledge and is best performed
by testers with design knowledge. For best results, testers can collaborate
with designers and developers. e level of thoroughness and documenta-
tion depends on test strategy and goals. However, often enough, unit tests
are not well documented, and unit test defects are not entered into the bug
tracker. ere is not much to motivate the designer except project objectives
and leadership drive.