"Meet the authors of The SysML v2 Book: Weilkiens and Molnár"

📘 Sharing my lecture notes on Software Reliability and Analysis Tools. Maintaining dependable software requires both proactive analysis and continuous improvement in reliability. This lecture covers key concepts that connect error detection, correction, and prediction. 🔹 Static vs. Dynamic Analysis Tools – Compared based on their input, operation, and output in identifying defects before and during execution. 🔹 Debugging Process – Key activities and guidelines for efficient error diagnosis and resolution. 🔹 Software Reliability – Defined as the trustworthiness or dependability of software, influenced by error location and execution profile. 🔹 Reliability Metrics – Includes MTTF, MTTR, MTBF, POFOD, and Availability for quantifying system dependability. 🔹 Reliability Growth Modelling – Used to predict when a target reliability level will be achieved during testing. These notes are designed to help students understand how systematic analysis and reliability modelling ensure software quality and long-term performance. #SoftwareEngineering #SoftwareTesting #SoftwareReliability #QualityAssurance #LectureNotes #ReliabilityMetrics

What is the actual difference between usage and definition in SysML v2? This is something I’ve been genuinely pondering. In SysML v2, it seems like elements can be defined by both elements of usage and definition. For example, a part can be defined by another part, or by a part def. Both can own attributes, and both can have other parts nested within them. So what’s the real conceptual difference between these two ideas? If both a part and a part def can own features and structure, then what’s the underlying need to distinguish between usage and definition at all? I’m sincerely asking the community, especially those who have been modeling deeply in SysML v2. How do you interpret this distinction in practice? Do you find the usage/definition separation essential, or would it be sufficient to simply have elements of usage, since an element of usage can also be the type / definition? #SysMLv2 #MBSE #DigitalEngineering #SystemsModeling #ModelBasedSystemsEngineering

I was asked in our internal 3-Day SysMLV2 training this exact question. But let me further clarify the ultimate question: “Why use definition if I can get all the same semantics from a usage?” So far the answer is a long list of technical differences between the two, but we are looking for a succinct and simple explanation for beginners. Read Brian’s post and the great responses specifically from Ed. What do you think? Note: a usage cannot type another usage (as shown in the image below), but subsetting provides similar(not the same) semantics.

Dear Systems Engineers, SysML V2 textual notations serve as an effective means to create accurate and reusable system models. I have constructed a simplified model of a home heating system for training purposes, and I am sharing a portion of it for your feedback and recommendations. The best practices adhered to in this model include: 1) Textual notation: I am convinced that the greatest benefit of SysML V2 is realized through the use of textual notations, while graphical notations should primarily serve for visualization. 2) Consistent application of definitions. I refrain from creating any usage element without an accompanying definition. Each usage element in my model is defined by a definition element, which greatly enhances reusability. 3) There is an absence of classifier behavior in SysML V2. I have employed a state usage to depict primary or classifier behavior. Please share your comments or suggestions, if any. #MBSE #SysML #QuestGlobal #digitaltransformation

I was exploring some blog posts today and laid my eyes on an interesting post about how often we programmers look at the documentation of something seeking an example, but all we see in technical references and formal introductions. The author then clarifies that this is because documentation is not all the same, and basically there is 4 types of it demonstrated in this beautiful walkthrough: https://lnkd.in/dFrHhGBu

Core Fundamentals that Scale With You To learn fast, build precisely, and stay relevant: 1. Data Structures and Algorithms – for the right solution, not just a solution 2. System Design – to architect, not just assemble 3. Technical English – to access global knowledge And one multiplier: Connect new concepts to what you already know. Mastery here compounds. Everything else is temporary. #SoftwareEngineering #SystemDesign #DSA #EngineeringExcellence

Two SysML v2 tool vendors recently clashed on LinkedIn about whose 𝗰𝗵𝗲𝗮𝘁 𝘀𝗵𝗲𝗲𝘁 was “correct.” But what is correctness anyway? English: https://lnkd.in/e6dwedXq German: https://lnkd.in/eYBSfwq5 Forget the fight. What does “𝗰𝗼𝗿𝗿𝗲𝗰𝘁 𝗦𝘆𝘀𝗠𝗟 𝘃𝟮” even mean? Depending on how you look at it, “correctness” can mean very different things, for example: • 𝗦𝘆𝗻𝘁𝗮𝗰𝘁𝗶𝗰 𝗰𝗼𝗿𝗿𝗲𝗰𝘁𝗻𝗲𝘀𝘀: The notation follows the formal grammar defined in the SysML v2 specification. • 𝗚𝗿𝗮𝗺𝗺𝗮𝘁𝗶𝗰𝗮𝗹 𝗰𝗼𝗿𝗿𝗲𝗰𝘁𝗻𝗲𝘀𝘀: Model elements are used in valid structural contexts, consistent with the metamodel. • 𝗦𝗲𝗺𝗮𝗻𝘁𝗶𝗰 𝗰𝗼𝗿𝗿𝗲𝗰𝘁𝗻𝗲𝘀𝘀: The model expresses the intended meaning — it makes sense in the engineering domain. • 𝗠𝗲𝘁𝗵𝗼𝗱𝗶𝗰𝗮𝗹 𝗰𝗼𝗿𝗿𝗲𝗰𝘁𝗻𝗲𝘀𝘀: The model follows sound modeling practices and process conventions. • 𝗟𝗶𝗻𝘁𝗲𝗿 𝗰𝗼𝗿𝗿𝗲𝗰𝘁𝗻𝗲𝘀𝘀: Style and consistency checks pass, i.e. naming, completeness, and structure are clean. • 𝗖𝗵𝗲𝗮𝘁-𝘀𝗵𝗲𝗲𝘁 𝘀𝗶𝗺𝗽𝗹𝗶𝗳𝗶𝗰𝗮𝘁𝗶𝗼𝗻𝘀: Simplified notations are acceptable if they support learning without distorting meaning. 𝗧𝗮𝗸𝗲𝗮𝘄𝗮𝘆: Before arguing about who’s right, make sure you agree on what “right” even means. #setrends, #SysMLv2, #MBSE, #ModelBasedSystemsEngineering, #SystemsEngineering, #DigitalEngineering, #SysIDE, #DassaultSystemes, #Sensmetry, #EngineeringTools, #ModelAsCode, #ProductVelocity, #FormalMind, #SETrends, Udo Nink, Andrius Armonas, Saulius Pavalkis, Juozas Vaicenavicius, Dassault Systèmes, Sensmetry

Final take - Do you really need MBSE? Short answer: you always need SE. Whether you need full MBSE depends on complexity and risk. MBSE done right takes time, skills, and money. Go MBSE when… -System complexity, interfaces, or variants are growing fast.Long lifecycle, reuse/product lines, or high change rates demand impact analysis. Use a lightweight model-based approach when… -You want decisions and interfaces visualized, but don’t need a full data backbone yet. -Start with architecture + interfaces, a clear notation/ontology, and minimal linking that supports real decisions. Probably skip full MBSE for… -Routine, well-known, low-risk work with few interfaces and short lifetimes. -Small teams delivering repeatable solutions where documents suffice. Finally a best practice approach is applying MBSE principles to certain aspects of the development workflow, e.g. System Architecture, Design, letting others document based, and have a good linked data approach to ensure proper traceability. MBSE is a means, not a mandate. Choose the least modeling that enables the most confident decisions. #tdse25 #GfSE #MBSE #SystemsEngineering

Free & Fair's CEO and Chief Scientist Joseph Kiniry shares our new long-form article on Rigorous Digital Engineering. This is the methodology we are using in the Mobile Voting Core Cryptography project (called "VoteSecure"), as well as in past projects, like ElectionGuard, which we created for Microsoft. https://lnkd.in/gNMNUQVM https://lnkd.in/djASNmb