TESSY

TESSY is an automated dynamic testing tool for embedded C and C++ software, designed for safety-critical development projects where code coverage measurement is a certification requirement. It handles unit testing, module testing, and integration testing with full support for statement, branch, decision, MC/DC, and modified condition combination (MCC) coverage metrics.

The tool automates the three most labour-intensive parts of embedded testing: interface analysis (automatically parsing function signatures to determine inputs and outputs), test driver generation (creating the harness code that invokes the function under test), and stub function creation (replacing called functions with controllable substitutes). This automation eliminates the manual harness-writing effort that consumes weeks on safety-critical projects.

Classification Tree Editor (CTE)

TESSY includes a graphical Classification Tree Editor for systematic test case design. Engineers define input partitions and boundary conditions visually, and TESSY generates the corresponding test vectors. This approach satisfies the systematic test design requirements of ISO 26262 Part 6 and IEC 61508 Part 3.

Regression and Batch Testing

Test suites execute in batch mode via command line, integrating directly into CI/CD pipelines (Jenkins, GitLab CI, Azure DevOps). When source code changes, TESSY re-runs affected tests and regenerates coverage reports, making regression testing automatic rather than manual.

Requirements Traceability

TESSY imports and exports requirements in ReqIF format, linking test cases to requirements for bidirectional traceability. This is mandatory for ISO 26262 ASIL C/D projects and simplifies auditor interactions during safety assessments.

TESSY vs Other Unit Testing Tools for Embedded C/C++

When evaluating unit testing and code coverage tools for embedded C and C++ projects, engineering teams typically compare TESSY against alternatives such as VectorCAST, Parasoft C/C++test, and LDRA Testbed. TESSY’s distinguishing capability is its automated test generation workflow: the tool performs interface analysis on function signatures, generates test drivers and stubs automatically, and provides systematic test case design through the Classification Tree Editor. This reduces the manual effort of writing test harnesses, a task that can consume weeks on safety-critical projects requiring MC/DC coverage.

For teams working under ISO 26262, IEC 61508, or DO-178C, TESSY provides pre-qualified tool classification documentation that simplifies the tool qualification process required by functional safety standards. The tool supports all coverage levels commonly required by safety assessors, statement, branch, decision, MC/DC, and modified condition combination (MCC), with traceability from requirements (ReqIF) through test cases to coverage results. Automated test generation combined with batch-mode CI/CD execution (Jenkins, GitLab CI) makes TESSY practical for regression testing in continuous integration environments where embedded C code coverage measurement must be repeatable and auditable.

Why Buy from GSAS

GSAS Micro Systems provides TESSY licensing in India with INR invoicing, onboarding training, CI/CD integration consulting, and ongoing technical support. Our functional safety engineers in Bengaluru, Hyderabad, and Pune help automotive, aerospace, and industrial teams deploy TESSY into their existing development workflows and achieve the coverage levels required by their target safety standard.