Gain a system-level perspective and understand how to achieve system safety.
This course brings the essential understanding of the safety of technical systems, the most common pitfalls, concepts, and techniques for providing safety. From introducing the key concepts from system engineering and requirements engineering, the lectures and exercises make the connection of these concepts with the key safety precursors and prescriptions. The course will give you all the relevant insights into system safety terminology and system safety process, focusing in-depth on functional safety and safety functions as the most common safety prescription in today’s systems, giving industry-relevant examples. Finally, the course provides you with insights into all quantitative and qualitative measures to attest to the safety integrity of the safety functions, including the methodology to improve and prove the safety integrity of the safety-related system.
Course topics:
Systems, system engineering lifecycle, system-level design approach with regard to safety
The system and its boundaries, system environment, context, and interactions with other systems
Basic principles of specific system life cycle phases, such as requirements engineering, design synthesis, realization, integration, verification, and validation
Integrative safety process and its phases
Safety terminology such as hazard, risk, failure, fault, and error
Basic risk evaluation, including risk matrices/graphs
The influence of various factors on system safety, including the standards, human factor, security, management, and software
Functional safety, safety functions, and their application in technical systems
Understand why some systems are safety-critical, and what are the most common pitfalls in the system design which cause dangerous system failures. The lecture discusses means of system delineation from the environment in the design, as well as traceability in the projects and processes which must make sure that the system requirements and intended functions are correctly implemented, verified and validated.
Analyze and decompose the system, including its features, to identify components, system boundaries, and safety-critical elements.
Position system requirements elicitation as a key safety precursor, together with the definition of functional requirements with safety requirements and their relations. The lecture provides some key methods for requirement elicitation and gives insight into the correct construction of the safety requirement specification with an inherent view to traceability.
Create and categorize a requirements table using proper prefixes and Kano analysis, then prepare to discuss stakeholder completeness and potential requirement removal.
Learn what constitutes safety and how exactly the systems fail, introducing for the first time, and discussing the concepts such as hazard, risk, faults, errors and failures. The lecture gives an overview of how hazard and risk analysis is performed and how the risks are correctly evaluated.
Analyze hazards and failure modes for selected functions, fill in the hazard and risk evaluation sheet, and describe the failure chain leading to potential accidents.
Laying out ground for having safety considerations and all relevant safety processes built into the project development lifecycle. The lecture details each phase and makes connections with the traditional processes in engineering and project management, emphasizing on the need for proactive safety from the inception of the project idea (pre-project phase) all the way into deployment.
Quantitatively assess and evaluate the risk of hazards H1, H2, and H3, implement safety measures for unacceptable risks, and re-evaluate their acceptability.
2 hours 30 minutes
M5: Functional safety (see DEMO video)
Main concepts and architectures in the field of functional safety are introduced, with the correct positioning of the equipment under control (EUC), EUC control system, safety-related system and the safety functions and key principles upon which they operate.
Select a hazard from previous exercises, define a top-level safety requirement, derive technical safety requirements ensuring traceability, and update the system requirement specification with proper Functional Safety (FuSa) terminology.
Learn how to correctly define safety functions in the context of functional safety, starting from the idea, system requirements definition, safety requirements, hazard and risk analysis and risk evaluation to the specific safety function design.
Participants are required to apply the concepts by looking at the selected functional safety standards this time, as well as to practice the safety function definition in their group assignments.
By having safety functions defined, now the “invisible” requirement of safety integrity of safety functions is laid out. The lecture provides insight on how the safety functions are attested for reliability against random failures and introduces key metrics from the reliability theory for the purpose, such as failure probability, reliability and failure rate. Finally, the lecture contrasts these metrics with what is required by the functional safety standards.
Use the provided data to calculate and plot failure rates, estimate the constant failure rate, MTTF, and compare these with ASIL requirements, and calculate failure probability and reliability.
Safety functions are usually requiring more than one system component to be able to bring the system to a safe state. This means that safety integrity might need to be provided for a composite architecture, where each component’s reliability affects the reliability of the whole. The lecture provides insights into how the composite system is modeled for reliability, introducing reliability block diagrams and the basic calculus for series and parallel (redundant) system configurations.
Draw a high-level SRS architecture and a reliability block diagram for the safety function, calculate the composite reliability using provided or assumed component data, and verify if the safety function meets SIL/PL requirements.
Safety integrity requirements might be hard to achieve, requiring improvements in safety function architecture to meet the reliability goal. In the lecture, various redundant configurations are discussed, as well as diversity principles, with insights on how these concepts are brought in and modeled for reliability with the appropriate calculations and considerations for common cause failures.
Create an RBD for the SRS, calculate system reliability, assess risk according to MEM, and improve reliability.
Now the students get the final listing of all relevant safety integrity metrics and the usual requirements from the standards, which need to be provided and met to formally prove the safety integrity of safety functions and argument the claims in the safety case presented for the audit. All key concepts are discussed, such as safe vs dangerous failures, diagnostics coverages and safe failure fraction. Finally, the lecture introduces the concept of system availability, which should not be overly diminished by the operation of safety functions.
Update the data to include failures, calculate SFF and DC for each component, verify SIL compliance with the standard, introduce redundancy to adjust HFT, and reassess the results. To close the safety case, determine any additional demonstrations required for the SRS.
The lecture gives example of how the safety integrity level is calculated for the safety functions according to the exemplary functional safety standards. First, a technical concept for the safety functions is given, and then the reliability is modeled according to the practices laid out in the previous lectures, which are then contrasted with the provisions from the functional safety standards.
Students are required to perform this calculation for their own example in the assignment, as a continuation of the previous assignment.
Final lecture gives a recap on all the required safety aspects to be considered when designing safe systems, bringing in additional important non-technical aspects, such as human factors, legislative aspect, safety roles, and the most importantly, safety culture within the company, its management and its employees who design the system.
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1 hour
Final exam
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none
1 hour 30 minutes
Requirements
Software: Chrome browser. Hardware: Computer with an Internet connection, working speakers, and microphone. Prior knowledge: Students should have basic engineering knowledge in either one of the following disciplines: electrical engineering, computer engineering, or mechanical engineering.
Course Features
Course IDNIT-FSBA-01
Live classes30
Self-paced classes30
SkillAdvanced
This course is currently not available for individual enrollment. You can ask to be added to the waiting list or make a custom order for groups by contacting us below.
€249€99
If you would only like to listen to lectures at your own pace, with no exercises, live sessions and exams, no problem!
In case you bought the course previously, you can get your course details and access information by entering the e-mail address you used to register for the course below.
In case you purchased the book Systems, Functions and Safety from Springer you are entitled to a 100% discount voucher for the video lectures. Please prepare the proof of purchase and write to us here.
