Testing embedded system errors without changing the source code:
Automated Fault Injection function for TESSY 4.1 from Razorcat
Tamworth 9 January 2018
Razorcat, manufacturer of test tools for the development of embedded software, has announced that the forthcoming release (4.1) of the TESSYunit and integration test tool will support automated fault injection.
With automated fault injection, developers of hardware and software for embedded systems and components can conveniently generate and manage test cases to be implemented in unit tests, integration tests and component tests automatically without changing the source code – saving time and money.
Classically, whenever 100% code coverage cannot be achieved with normal test cases, fault injections are applied manually. This can be by adding testing code, by code replacements using compiler macros, by replacing functions (stubbing) or by changing variable values using debug tools. These methods have the disadvantage that either they need to be added and removed manually or the instrumentation of the source code remains in place within production code. Given that it is most probably the test engineer who first identify the need for a fault injection, if the code needs to be changed, the subsequent corrections to the code will ned to be subject to the software development approvals process required by the safety standards. Such an iteration highly increases development time and cost.
Automated testing without source code changes
In TESSY 4.1, however, fault injection is automated and does not remain in the source program. The error injections are defined directly in the flow chart of the function within the TESSY environment. (see Fig 1 – below)
Save, manage and reuse fault injections
Test cases with automated fault injection have a special flag and will be documented within the test report. When all test cases are executed, these special test cases can be included or excluded from the test execution. All fault injections are conveniently stored and managed in TESSY. In this way, fault injections can be assigned to one or more test cases in a user-friendly way and will be effective at the desired location even after source code changes when doing regression testing. (see Fig 2 below).
In the UK, TESSY is available from high reliability and safety-critical tools specialist, Phaedrus Systems.
Notes for Editors
TESSY version 4.1, will be presented at embedded world 2018 (Hall 4, booth 4-434).
High resolution copies of the images are available at
About Phaedrus Systems
Phaedrus Systemsis the UK’s leading specialist in the support of engineers at all stages of embedded safety-critical and high-integrity projects. Tools available include requirements capture for IEC 61508, EN 50128 and nuclear applications; requirements tracking and competency tools; estimation software; SIL3 RTOS; hi-rel embedded database; compiler validation reports and reliability/failure software. Consultants have experience working on automotive, rail and aerospace applications, meeting standards such as IEC 61508 SIL4, and D0178B. Backing these is a wide range of other relevant embedded tools. Phaedrus Systems is based in Tamworth, Staffordshire. More information is available on the website
About Razorcat
Razorcat Development GmbH has been creating testing tools for software development of embedded systems since 1997. The unit and integration testing tool TESSY is certified to IEC 61508 and ISO 26262, and is being used in a large number of software projects across all branches of industry for the verification of safety-critical and high-quality software. Together with the Integrated Test Environment (ITE), Test Operator Platform (TOP) and Check Case Definition Language (CCDL) tools, Razorcat offers solutions for all stages of the testing process. Services like test management, testing, consulting and seminars provide additional support for customers around the world.
More information about Razorcat is available at .
Company Contacts
Phaedrus Systems
ChrisHills, CTO
Tel: +44 (0) 1827 259546
E-Mail:
Razorcat Development GmbH
Witzlebenplatz 4,
14057 Berlin
Telefon: +49 (0) 30 53 63 57 0
Fax: +49 (0) 30 53 63 57 60
E-Mail:
Fig 1 New in TESSY 4.1: Function for flow graph based fault injection
Fig 2 Fault injections will be edited directly within the flow chart and managed by TESSY