Formal Verification of Embedded Software for SIL-4 Safety Systems

At Codewit Solutions, we specialize in the formal verification of embedded software for safety-critical systems, such as railway signals and bridge controls. Our methodology guarantees that control algorithms function flawlessly under all conditions, up to and including the highest Safety Integrity Level (SIL-4).

Static Code Analysis and Mathematical Proof

The core of our approach consists of advanced static code analysis combined with mathematical proof. This allows us to model and verify every possible execution path of the software, long before the code is implemented in the physical system.

// Example of verified state logic
if (sensor_input == SAFE) {
    set_signal(GREEN);
} else if (sensor_input == WARNING) {
    set_signal(YELLOW);
} else {
    // Unexpected state - safe shutdown
    initiate_safe_shutdown();
    log_error(ERROR_CODE_UNEXPECTED_INPUT);
}

Through these rigorous processes, we eliminate the chance of runtime errors that could lead to catastrophic system failure. Our verification reports are used to comply with strict standards such as EN 50128 for railway applications.

Binary-Green Logic in Practice

The binary principle (good/faulty, safe/unsafe) is visually translated into a green theme in our verification dashboards. A successful verification results in a "green light" for the next development phase.