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, […]
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 special requirements apply for the tools […]
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.
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 […]
IEC 61508, ISO26262, DO 178C, ISO 25119: Have you ever encountered these abbreviations in your professional life? If so, there is a high probability that you are already implementing functional safety projects in your company or that you are entering the market in the near future. Perhaps you have already made the experience, or at […]
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 […]
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 The classic approaches, especially the waterfall model and the V-model, seem to be more and more outdated.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 […]
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. […]
In the first part (Link) I explained the basic idea, which is behind the tool qualification. I have already given an overview of the four most frequently used measures. In this article, I will discuss each of these 4 measures in more detail and name the respective advantages and disadvantages.
Many companies and project teams that carry out projects for the first time in the field of functional safety have the impression that the topic of tool qualification is critical to success and involves a great deal of effort. Although this issue is, of course, important and also involves a certain cost effort, the subject […]