TY - CHAP A1 - Möhrle, Felix A1 - Bizik, Kai A1 - Zeller, Marc A1 - Höfig, Kai A1 - Rothfelder, Martin A1 - Liggesmeyer, Peter T1 - A Formal Approach for Automating Compositional Safety Analysis Using Flow Type Annotations In Component Fault Trees T2 - Proceedings of the 27th European Safety and Reliability Conference (ESREL): Safety and Reliability – Theory and Applications., Portorož, Slovenia: Taylor & Francis (CRC Press). N2 - Safety assurance is a major challenge in the design of modern embedded systems that has become increasingly difficult in recent years. Growing system sizes and the rise of Cyber-Physical systems confront safety engineers with large sets of configurations to be analyzed. Current approaches are usually carried out at design time and do not address the need for automated assessments in the field. With Component Fault Trees (CFTs) there exists a component-based methodology that enables an efficient modular composition of safety artifacts. The combined model is a system-level CFT that can be analyzed by means of popular Fault Tree Analysis techniques that are widely accepted in the industry. However, when composing models, their interfacing elements must be connected manually which impedes the automation of the procedure. In this work, we introduce the notion of flow types that represent a particular kind of component interaction and define a taxonomy of related failure behavior. By annotating CFTs with types, a machine-readable vocabulary is provided that allows for an automated interconnection of their interfaces. This way, the automatic composition of models according to system architecture is enabled, allowing for automated safety assessments on system-level. We demonstrate the feasibility of our approach using an example ethylene vaporization unit. KW - Compositional safety analysis KW - Flow type annotations KW - CFT Y1 - 2017 ER - TY - CHAP A1 - Höfig, Kai A1 - Zeller, Marc A1 - Heilmann, Reiner T1 - ALFRED: a methodology to enable component fault trees for layered architectures T2 - 2015 41st Euromicro Conference on Software Engineering and Advanced Applications (SEAA), August 2015,Funchal, Portugal. IEEE. N2 - Identifying drawbacks or insufficiencies in terms of safety is important also in early development stages of safety critical systems. In industry, development artefacts such as components or units, are often reused from existing artefacts to save time and costs. When development artefacts are reused, their existing safety analysis models are an important input for an early safety assessment for the new system, since they already provide a valid model. Component fault trees support such reuse strategies by a compositional horizontal approach. But current development strategies do not only divide systems horizontally, e.g., By encapsulating different functionality into separate components and hierarchies of components, but also vertically, e.g. Into software and hardware architecture layers. Current safety analysis methodologies, such as component fault trees, do not support such vertical layers. Therefore, we present here a methodology that is able to divide safety analysis models into different layers of a systems architecture. We use so called Architecture Layer Failure Dependencies to enable component fault trees on different layers of an architecture. These dependencies are then used to generate safety evidence for the entire system and over all different architecture layers. A case study applies the approach to hardware and software layers. KW - Fault trees KW - Layered architecture Y1 - 2015 SP - 167 EP - 176 ER - TY - CHAP A1 - Höfig, Kai A1 - Zeller, Marc A1 - Schorp, Konstantin T1 - Automated failure propagation using inner port dependency traces T2 - 2015 11th International ACM SIGSOFT Conference on Quality of Software Architectures (QoSA), Mai 2015, Montreal, QC, Canada. N2 - Safety assurance is a major challenge in the design of complex embedded and Cyber-physical Systems. Especially, changes and adoptions during the design or run-time of an embedded system invalidate former safety analyses and require an adaptation of the system's safety analysis models. In this paper, we present a methodology to fill up empty safety analysis artifacts in component fault trees using so-called inner port dependency traces to describe failure propagation. Thus, enabling a imprecise but rapid safety analysis of an entire system at early development stages or during system run-time for the automated certification of Cyber-physical Systems. We evaluate our approach using case study from the automotive domain. KW - Failure propagation KW - Port dependency traces KW - Cyber-physical Systems KW - Software safety Y1 - 2015 SP - 123 EP - 128 ER - TY - CHAP A1 - Jung, Jessica A1 - Höfig, Kai A1 - Domis, Dominik A1 - Jedlitschka, Andreas A1 - Hiller, Martin T1 - Experimental comparison of two safety analysis methods and its replication T2 - 2013 ACM / IEEE International Symposium on Empirical Software Engineering and Measurement, December 2013, Baltimore, MD, USA. N2 - (Background) Empirical Software Engineering (SE) strives to provide empirical evidence about the pros and cons of SE approaches. This kind of knowledge becomes relevant when the issue is whether to change from a currently employed approach to a new one or not. An informed decision is required and is particularly important in the development of safety-critical systems. For example, for the safety analysis of safety-critical embedded systems, methods such as Failure Mode and Effect Analysis (FMEA) and Fault Tree Analysis (FTA) are used. With the advent of model-based systems and software development, the question arises whether safety engineering methods should also be adopted. New technologies such as Component Integrated Fault Trees (CFT) come into play. Industry demands to know the benefits of these new methods over established ones such as Fault Trees (FT). (Methods) For the purpose of comparing CFT and FT with regard to the capabilities of the safety analysis methods (such as quality of the results) and to the participants' rating of the consistency, clarity, and maintainability of the methods, we designed a comparative study as a controlled experiment using a within-subject design. The experiment was run with seven academic staff members working towards their PhD. The study was replicated with eleven domain experts from industry. (Results) Although the analysis of the tasks' solutions showed that the use of CFT did not yield a significantly different number of correct or incorrect solutions, the participants rated the modeling capacities of CFT higher in terms of model consistency, clarity, and maintainability. (Conclusion) From this first evidence, we conclude that CFT have the potential of being beneficial for companies looking for a safety analysis approachfor projects using model-based development. KW - Safety Analysis KW - CFT KW - FMEA Y1 - 2013 SN - 978-0-7695-5056-5 SP - 223 EP - 232 ER - TY - CHAP A1 - Jung, Jessica A1 - Jedlitschka, Andreas A1 - Höfig, Kai A1 - Domis, Dominik A1 - Hiller, Martin T1 - A controlled experiment on component fault trees T2 - International Conference on Computer Safety, Reliability, and Security (SAFECOMP 2013) N2 - In safety analysis for safety-critical embedded systems, methods such as FMEA and fault trees (FT) are strongly established in practice. However, the current shift towards model-based development has resulted in various new safety analysis methods, such as Component Integrated Fault Trees (CFT). Industry demands to know the benefits of these new methods. To compare CFT to FT, we conducted a controlled experiment in which 18 participants from industry and academia had to apply each method to safety modeling tasks from the avionics domain. Although the analysis of the solutions showed that the use of CFT did not yield a significantly different number of correct or incorrect solutions, the participants subjectively rated the modeling capacities of CFT significantly higher in terms of model consistency, clarity, and maintainability. The results are promising for the potential of CFT as a model-based approach. KW - Safety-critical embedded systems KW - FMEA KW - CFT Y1 - 2013 SP - 285 EP - 292 PB - Springer CY - Berlin, Heidelberg ER - TY - CHAP A1 - Möhrle, Felix A1 - Zeller, Marc A1 - Höfig, Kai A1 - Rothfelder, Martin A1 - Liggesmeyer, Peter T1 - Automating compositional safety analysis using a failure type taxonomy for component fault trees T2 - Risk, Reliability and Safety: Innovating Theory and Practice: Proc. of ESREL N2 - Safety assurance is a major challenge in the design of today’s complex embedded systems and future Cyber-physical systems. Changes in a system’s architectural design invalidate former safety analyses and require a manual adaptation of related safety analysis models in order to restore consistency. In this work, we present an approach for automating the compositional assembly of Component Fault Trees by automatically generating mappings between their input and output failure modes. Therefore, we propose a taxonomy of failure types for annotating model elements and deriving a model of the failure propagation. This way, automatic and system-wide safety analyses can be executed and easily repeated after making modifications to the system’s architecture. We demonstrate the feasibility of our approach using an example ethylene vaporization unit from an industrial domain. KW - Compositional safety analysis KW - CFT Y1 - 2016 SP - 1380 EP - 1387 ER - TY - CHAP A1 - Möhrle, Felix A1 - Zeller, Marc A1 - Höfig, Kai A1 - Rothfelder, Martin A1 - Liggesmeyer, Peter T1 - Automated compositional safety analysis using component fault trees T2 - Proceedings of the IEEE International Symposium on Software Reliability Engineering Workshops (ISSREW 2015), November 2015, Gaithersburg, MD. N2 - Safety assurance is a major challenge in the design of today's complex embedded systems and future Cyber-physical systems. Especially changes in a system's architectural design invalidate former safety analyses and require an adaptation of related safety analysis models in order to restore consistency. In this work, we present an approach for automatically generating mappings between failure ports in compositional safety analysis models. This way, automatic and system-wide safety analyses are enabled that can be easily repeated after making modifications to the system's architecture. We demonstrate the feasibility of our approach using a case study from the automotive domain. KW - Safety KW - Fault trees KW - Adaption models KW - Automotive Engineering Y1 - 2015 SP - 152 EP - 159 ER - TY - CHAP A1 - Zeller, Marc A1 - Höfig, Kai T1 - INSiDER: Incorporation of system and safety analysis models using a dedicated reference model T2 - 2016 Annual Reliability and Maintainability Symposium (RAMS) N2 - In order to enable model-based, iterative design of safety-relevant systems, an efficient incorporation of safety and system engineering is a pressing need. Our approach interconnects system design and safety analysis models efficiently using a dedicated reference model. Since all information are available in a structured way, traceability between the model elements and consistency checks enable automated synchronization to guarantee that information within both kind of models are consistent during the development life-cycle. KW - Safety KW - CFT Y1 - 2016 SP - 1 EP - 6 ER - TY - CHAP A1 - Zeller, Marc A1 - Höfig, Kai A1 - Schwinn, Jean-Pascal T1 - ArChes—Automatic generation of component fault trees from continuous function charts T2 - 2017 IEEE 15th International Conference on Industrial Informatics (INDIN), July 2017, Emden, Germany. N2 - The growing size and complexity of software in embedded systems poses new challenges to the safety assessment of embedded control systems. In industrial practice, the control software is mostly treated as a black box during the system's safety analysis. The appropriate representation of the failure propagation of the software is a pressing need in order to increase the accuracy of safety analyses. However, it also increase the effort for creating and maintaining the safety analysis models (such as fault trees) significantly. In this work, we present a method to automatically generate Component Fault Trees from Continuous Function Charts. This method aims at generating the failure propagation model of the detailed software specification. Hence, control software can be included into safety analyses without additional manual effort required to construct the safety analysis models of the software. Moreover, safety analyses created during early system specification phases can be verified by comparing it with the automatically generated one in the detailed specification phased. KW - Industrial Informatics KW - CFT KW - Function charts Y1 - 2017 ER - TY - CHAP A1 - Armengaud, Erik A1 - Macher, Georg A1 - Massoner, Alexander A1 - Frager, Sebastian A1 - Adler, Rasmus A1 - Schneider, Daniel A1 - Longo, Simone A1 - Melis, Massimiliano A1 - Groppo, Riccardo A1 - Villa, Federica A1 - O’Leary, Padraig A1 - Bambury, Kevin A1 - Anita, Finnegan A1 - Zeller, Marc A1 - Höfig, Kai A1 - Papadopoulos, Yiannis A1 - Hawkins, Richard A1 - Kelly, Tim T1 - DEIS: Dependability Engineering Innovation for Industrial CPS T2 - Advanced Microsystems for Automotive Applications 2017 N2 - The open and cooperative nature of Cyber-Physical Systems (CPS) poses new challenges in assuring dependability. The DEIS project (Dependability Engineering Innovation for automotive CPS. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 732242, see http://www.deis-project.eu) addresses these challenges by developing technologies that form a science of dependable system integration. In the core of these technologies lies the concept of a Digital Dependability Identity (DDI) of a component or system. DDIs are modular, composable, and executable in the field facilitating (a) efficient synthesis of component and system dependability information over the supply chain and (b) effective evaluation of this information in-the-field for safe and secure composition of highly distributed and autonomous CPS. The paper outlines the DDI concept and opportunities for application in four industrial use cases. KW - Industrial CPS KW - Dependability Engineering KW - Automotive Applications Y1 - 2018 SP - 151 EP - 163 PB - Springer CY - Cham ER -