
How to Design Extended Finite State Machine Test Models in Java 167
errors. To measure the error detection power of the generated tests, we wrote a software
simulation of a SIM chip in Java and used Jumble to generate 298 different mutants of that
simulation. Each mutant is like a potential bug in the SUT. Then, we generate different
size test suites and measure what percentage of the mutants/bugs is detected by the test
suite and what percentage of the lines of code in the SUT is executed by the test suite.
Figure 6.12 shows that the bug-detection rate rises rapidly up to a test length of 1000,
and then more slowly to the maximum of 85% of mutants