1. 04/27/2006 Dr. Claudia Nowak Slide 1 Systems with safety-related software according to IEC 61508-3 – costs out of control? Experience from a development project

2. 04/27/2006 Safety-related software (IEC 61508-3) Dr. Claudia Nowak Slide 2 Field Device Project: Components of Development Software as part of development project Sensor Design Electronic Design Mechanical Design Software Design

3. 04/27/2006 Safety-related software (IEC 61508-3) Dr. Claudia Nowak Slide 3 Software development process Main activities of software development process: Management activities Who, what, when, how? Software specification What shall the software do? Software design How to realise the software? Software verification Do we develop the correct software? Software validation Did we develop the software correctly?

4. 04/27/2006 Safety-related software (IEC 61508-3) Dr. Claudia Nowak Slide 4 Safety-related software development process Software criticality analysis SW specification and realisation SW verificationSW validation Software (safety) requirements Software concept SW architecture Software test specification Software test plan Software HAZOPSW fine design SW functional safety management plan Software module tests SW coding Integration tests Management Documentation (Safety Manual, …) Configuration management Change management Requirements and error tracking Functional safety assessment New/revised elements Gap

5. 04/27/2006 Safety-related software (IEC 61508-3) Dr. Claudia Nowak Slide 5 Tools Tool allocation to software V-model Requirements and validation test tool Programming enviroment and analysis tool Design tool Test tool for automatic testing SCA and HAZOP tool Software (safety) requirements Software architecture Software fine design Software module design Software coding Software module tests Software integration tests Software function tests Software validation Safety criticality analysis Software HAZOP

6. 04/27/2006 Safety-related software (IEC 61508-3) Dr. Claudia Nowak Slide 6 Requirements Specification und Testing The software shall convert the sensor signal to an analog pressure signal.

7. 04/27/2006 Safety-related software (IEC 61508-3) Dr. Claudia Nowak Slide 7 Benefit from pilot project Functional Safety Management Plan (FSM) Re-use of pre-defined requirements and related tests Tools Document templates Coding guidelines Safety manual Lessons Learned Structured development Verification and documentation

8. 04/27/2006 Safety-related software (IEC 61508-3) Dr. Claudia Nowak Slide 8 Cost aspects for SIL projects More time (and money) to be spent during conception and specification phase of SIL projects (plus 30 % compared to non-SIL projects) More accurate project planning, scheduling, specification, etc. Less changes at advanced project phases and more precise planning of software changes Change Control Board. Slightly increasing costs compared to earlier development because more time is needed due to more documentation and verification. Benefit: These activities increase quality and safety of the product!

9. 04/27/2006 Dr. Claudia Nowak Slide 9 Thank you very much for your attention