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DO-178B/C, ISO 26262, IEC 61508: How many level of Software requirements are necessary and useful?

In my daily projects in the automotive and industrial automation industry I’m continually confronted with the question of how many levels of software requirements have to be written. That’s an interesting question, especially if we take the aerospace industry also into account. Therefore, I want to highlight in this blog post this topic a bit […]

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FMEA – A powerful method, but not for software!

In the functional safety, there is a method which is always used – the FMEA (Failure Mode Effects Analysis). In particular, on system and hardware level the FMEA supports systematic analysis. There are also variants such as the FMECA and the FMEDA. In this blog post I use only the term FMEA. In project practice […]

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ISO 26262: Fault Injection Test – Do you really need it?

The ISO 26262 defines the fault injection test as a test method for the system integration and unit test level (ISO 26262-4 [System] Tables 5, 8, 10, 13, 15, 18; ISO 26262-5 [Hardware] Table 11; ISO 26262-6 [software] tables 10, 13). This method has certainly a large part in the implementation of a possible error-free […]

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Functional Safety

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Compiler for safety critical software – What needs to be done?

The compiler is the central „tool“, which is required for every software development. It forms the link between the human-readable high-level source code (e.g., C and C ++) and the machine code, interpretable for the hardware processor. For the development of safety critical software according to relevant functional safety standards such as ISO26262 (car), EN50128 […]

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Freedom of Interference – The practice in Industry!

In the last blog (June 2017), I explained the principle of Freedom of Interference. The example used was based on the automotive industry and the ISO26262. Now I would like to consider Freedom of Interference with respect to the industry sectors railway, aviation and automotive and share my industry experiences with you. Share on LinkedinShare […]

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Challenges when determining the structural source code coverage on the target!

The proof of a 100% structural source code coverage is required by almost all functional safety standards (IEC61508, ISO26262, DO 178C, etc.). In the individual SIL / ASIL levels, only the type of source code coverage is differentiated. Essentially, the Statement Coverage (low SIL / ASIL Level), the Branch Coverage and the MC / DC […]

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DO178

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Compiler for safety critical software – What needs to be done?

The compiler is the central „tool“, which is required for every software development. It forms the link between the human-readable high-level source code (e.g., C and C ++) and the machine code, interpretable for the hardware processor. For the development of safety critical software according to relevant functional safety standards such as ISO26262 (car), EN50128 […]

Fotolia_73259178_S

Freedom of Interference – The practice in Industry!

In the last blog (June 2017), I explained the principle of Freedom of Interference. The example used was based on the automotive industry and the ISO26262. Now I would like to consider Freedom of Interference with respect to the industry sectors railway, aviation and automotive and share my industry experiences with you. Share on LinkedinShare […]

Fotolia_11463533_S

Challenges when determining the structural source code coverage on the target!

The proof of a 100% structural source code coverage is required by almost all functional safety standards (IEC61508, ISO26262, DO 178C, etc.). In the individual SIL / ASIL levels, only the type of source code coverage is differentiated. Essentially, the Statement Coverage (low SIL / ASIL Level), the Branch Coverage and the MC / DC […]

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EN50128

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EN 50128: Configurable Systems – The solution?

Chapter 8 of EN 50128 specifies the requirements for systems that are configured by application data or application algorithms. This blog summarizes the essential requirements of the standard and the practice-oriented challenges of software-configurable embedded systems. At the first glance the configurability offers only advantages. The functional behavior of the entire system can be adjusted […]

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EN 50128 – Functional Safety in the railway industry

The standards EN50126, EN50128 EN50129 describe the functional safety in the railway industry. These standards implement the IEC61508 for this industry. The peculiarity of the rail industry with regard to functional safety is that the systems are to be certified by an governmental authority (in Germany the federal railway authority), before they are allowed to […]

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ISO26262

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ISO26262: Freedom of interference – What is that?

There are four essential measures in the development of safety-critical systems. Design of safe systems Measures to minimize random hardware errors Measures to minimize systematic hardware and software errors Organizational measures (management of functional safety) Particularly in the design of safe systems, the principle of Freedom of interference is a powerful measure. What’s this? The […]

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DO-178B/C, ISO 26262, IEC 61508: How many level of Software requirements are necessary and useful?

In my daily projects in the automotive and industrial automation industry I’m continually confronted with the question of how many levels of software requirements have to be written. That’s an interesting question, especially if we take the aerospace industry also into account. Therefore, I want to highlight in this blog post this topic a bit […]

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ISO 26262: configurable / calibratable Software – Chance or Risk?

Configurable Software Systems in ISO26262 are discussed in part 6 Annex C. This blog summarizes important requirements of the standard and shows practice-oriented challenges of software-configurable embedded systems. The use of calibration data in configurable systems offers a lot of advantages. The functional behavior of the entire system can be adjusted by simple and rapid […]

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IEC61508

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IEC61508: Specification – Architecture – Requirements; Is there any difference?

For an increasing number of systems in the industrial automation functional safety requirements must be fulfilled. The IEC61508 compliance must be demonstrated for the software development. On the other hand, there are commercial requirements which often severely limit the product development budget. The solution lies in an efficient development process that meets the safety-relevant requirements. […]

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DO-178B/C, ISO 26262, IEC 61508: How many level of Software requirements are necessary and useful?

In my daily projects in the automotive and industrial automation industry I’m continually confronted with the question of how many levels of software requirements have to be written. That’s an interesting question, especially if we take the aerospace industry also into account. Therefore, I want to highlight in this blog post this topic a bit […]

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Requirements Engineering

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RE Engineering – Aspects which even not considerd in RE theory!

In most of the requirement engineering publications, the focus is on management aspects. The collection and management of requirements is discussed extensively. In the following blog I discuss important aspects which are not sufficiently considered in the RE theory. I start with the definition of Requirement Engineering in the book „Requirements Engineering Fundamentals“ (Klaus Pohl, […]

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User Stories – The better Requirements?

The book „User Stories“ from Mike Cohn (ISBN 978-0321205681) has inspired me to think about the relationship between user stories and requirements. In software development, agile methods are often preferred in recent years. The classic approaches, especially the waterfall model and the V-model, seem to be more and more outdated. As a result, user stories […]

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Requirement/Code Reviews – The better TDD?

If a project getting difficulties with writing requirements, there is Test Driven Development (TDD) often referred to as the solution. Is that really the solution? If so, why TDD has not really become widely accepted in the software development up to now? In this blog I will express my thoughts about this topic. Share on […]

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Validation and Verification

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Implicit Testing – A good idea (Part 2)?

In the first part of the blog I defined the term „Implicit Testing“ and discussed root causes for the need of implicit tests. In the second part I will focus on the disadvantages of such tests and on possible solution approaches with the goal to avoid these disadvantages. Share on LinkedinShare on XingShare on TwitterShare […]

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Implicit Testing – A good idea (Part 1)?

In larger safety-critical projects, quite often I hear the following statement: „Well, the Requirement A is indirectly or implicitly proven with the test XY!“ Do you know this sentence as well? Have you ever experienced what can happen in late project phases when you have tested many requirements indirectly? The blog defines the term in […]

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Structural source code coverage and Requirements – Is there any dependency?

If you are newly engaged in the area of functional safety, then you will encounter fairly quickly the terms “structural source code coverage” and “requirements”. The specification of technical systems by requirements is, of course, also common in non-safety-critical areas. By contrast, the subject structural source code coverage is almost unknown outside safety-critical projects. In […]

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Config and Quality

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Quality Assurance in functional safety projects – Where is the difference?

The quality assurance checks the quality of the product. This is first of all an almost trivial statement. Depending on the definition of the term „product“, however, differentiate the responsibilities clearly. Do we monitor a production process or are we considering the assurance of quality in a software and electronics development? The following blog deals […]

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Configuration Management: A challenging task!

Do you know the following situation? A software project is restarted and the individual tasks are distributed within the project team. Sometime if (nearly) all roles are assigned – no one has thought about the configuration management. Often this role is quickly assigned to the project leader, because – so the assumption -there is anyway […]

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Security

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Security – A term that has many meanings!

Security is a topic which plays a key role for the success of topics like Internet of Things, Smart Home. If we consider the topic in more detail, it will be realized that it will be worthwhile, to separate the individual topics. It is important to be aware that the boundaries of the separate topics […]

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