Functional Safety Solutions

Our software team adheres to strict coding standards (like MISRA C/C++) and utilizes formal verification methods to ensure your software is as predictable as your hardware.

We support the team to development of software for safety functional systems where this process is  performed in accordance with the principles of functional safety as defined by IEC 50128.  We have experience in the areas where: 

• The software typically operates within a dual-processor architecture, which together form a redundant and fault-tolerant system. Both processors execute equivalent or complementary logic and continuously monitor each other’s outputs and internal states in order to detect discrepancies and enforce a safe system state in case of faults.
• The software lifecycle is implemented according to a V‑model approach, in which each development phase is associated with a corresponding verification activity. The process begins with the definition of software requirements derived from system-level safety requirements. Particular attention is given to the definition of fail-safe conditions and the behavior of the system in degraded or fault scenarios.
• The software architecture is developed to ensure proper partitioning of functions and to support the dual-CPU safety concept.Mechanisms such as cyclic execution, deterministic scheduling, watchdog supervision, and cross-comparison of outputs are integrated at this stage. The design ensures that no single fault can lead to a hazardous situation and that any divergence between the processors leads to a transition into a safe state

We help with implementation of the software using a restricted subset of the programming language compliant with MISRA guidelines. These rules are applied to eliminate ambiguous constructs and ensure predictable execution behavior, which is essential for safety-critical systems. The code avoids unsafe features such as uncontrolled pointer arithmetic, dynamic memory allocation (unless strictly justified), and implicit type conversions. The objective is to achieve a high level of code reliability and maintainability.

During implementation, we are using the static analysis tools (commonly referred to as linting tools) to verify compliance with MISRA rules and to detect potential issues such as dead code, unused variables, or non-deterministic constructs. All violations identified by the analysis are either corrected or formally justified, ensuring that the final code base conforms to the required safety standards. In addition to automated analysis, systematic code reviews are performed to confirm that the implementation is consistent with the design and that all safety mechanisms are correctly realized.

Testing activities are performed at multiple levels to ensure the correctness and safety integrity of the software. Unit testing verifies that individual modules behave as specified, including their handling of boundary conditions and erroneous inputs. Integration testing validates the interaction between modules and ensures correct communication and data exchange. Special attention is given to synchronization mechanisms and consistency checks between the processors.

A critical part of the verification strategy is structural coverage testing. Depending on the Safety Integrity Level (SIL), coverage metrics such as statement coverage, branch coverage, and Modified Condition/Decision Coverage (MC/DC) are applied. These metrics ensure that all relevant parts of the code are exercised during testing and that no unverified logic remains.

We help with analysis of the coverage report which also includes verification of safety-related paths, particularly those handling fault detection and safe state transitions in the CROSS-CPU architecture. Where the Coverage is missing we analyse/review the code to fill the gaps.

The implemented code is prepared for the Cyber security standards to eliminate potential vulnerabilities and bottlenecks from the Functional Safety standards perspective. This process includes:

• Input validation - to verify fields and proper values in the packets that are sent by network.
• All external communication channels protected by the TLS encryptions and sessions management.
• Security Error Handling - The error syslog messages created where the software recognizes improper system behavior or content of the packets.