|Unit Name||SAFETY INSTRUMENTED SYSTEMS|
|Unit Duration||1 Term (online) or 1 Semester (on-campus)|
Graduate Diploma of Engineering (Industrial Automation)
|Unit Creator / Reviewer||Fraser Maywood|
|Pre/Co-requisites||ME502 Programmable Logic Controllers
ME503 Industrial Process Control Systems
ME504 Industrial Instrumentation
|Mode of Delivery||On-Campus or Online|
|Unit Workload||10 hours per week:
Lecture - 1 hour
Tutorial Lecture - 1 hour
Practical / Lab - 1 hour (where applicable)
Personal Study recommended - 7 hours (guided and unguided)
Unit Description and General Aims
This unit addresses the concept of functional safety to reduce safety risks associated with the incorrect operation of electrical/electronic or programmable systems.
In this unit, the student will be introduced to applicable regulatory and standards framework for a range of industry sectors.
A series of sub-topics will address the philosophy of hazard identification, risk management and risk-based design of protection methods. The functional safety life-cycle will be explored in depth as will practical aspects of deploying the standards in practice. This will include Safety Integrity Level identification, system requirements design, design verification, functional safety assessment, commissioning, operations and maintenance and functional safety management.
On successful completion of this subject/unit, students are expected to be able to:
- Judge applicable regulations, international standards and risk identification processes.
Bloom’s Level 5.
- Participate in and make a valuable contribution to safety studies and set safety targets for Safety Instrumented Systems.
Bloom’s Level 5
- Plan and execute Safety Instrumented Systems projects in accordance with the safety life cycle requirements of internationally recognized standards.
Bloom’s Level 6.
- Verify and assure Safety Instrumented Systems performance across the safety life cycle in accordance with internationally recognized standards.
Bloom’s Level 5.
- Develop training and competency growth programmes to enable a company to comply with the functional safety management requirements of internationally recognized standards.
Bloom’s Level 6.
(e.g. Assignment - 2000 word essay (specify topic)
Examination (specify length and format))
|When assessed(e.g. Week 5)||Weighting (% of total unit marks)||Learning Outcomes Assessed|
|Week 5||15%||1, 2|
|Week 7||15%||4, 5|
|Final Week||45%||1, 2, 3, 4, 5|
Attendance / Tutorial Participation
Example: Presentation, discussion, group work, exercises, self-assessment/reflection, case study analysis, application.
|Continuous||5%||1, 2, 3, 4, 5|
Prescribed and Recommended Readings
- Safety Instrumented Systems: design analysis and justification: Paul Gruhn and Harry Cheddie. 2nd edition 2006. ISBN 1-55617-956-1 ISA, Research Triangle Park NC 27709 USA.
- D.J. Smith and K.G.L. Simpson, Safety critical systems handbook: a straightforward guide to functional safety: IEC 61508 (2010 edition) and related standards, 2010
- Layer of Protection Analysis: Simplified Process Risk Assessment (A CCPS Concept Book)
- W.M. Goble and H. Cheddie, Safety Instrumented Systems Verification: Practical Probabilistic Calculations, 2010
Number of peer-reviewed journals and websites (advised during lectures). Some examples are listed below.
- Engineering standard: IEC 61508:2010 Functional Safety of Electrical/ Electronic/ Programmable Electronic Safety-related Systems (E/E/PE, or E/E/PES).
- Engineering standard: IEC 61511:2004 Functional Safety - Safety instrumented systems for the process industry sector.
- Engineering Standard: IEC/EN 62061:2006 Safety of machinery: Functional safety of electrical, electronic and programmable electronic control systems.
- Engineering Standard: AS 4024.1:2014, Safety of Machinery.
- IDC notes and Reference texts as advised.
- Other material advised during the lectures.
One topic is delivered per contact week, with the exception of part-time 24-week units, where one topic is delivered every two weeks.
Topics 1 and 2
Process Safety Overview
1. What goes wrong and why
2. Hazard identification, risk assessment
3. Safety maturity model, ALARP and tolerable risk
4. System safety vs. safety management system
5. System safety process
6. Systematic failure avoidance: Quality control, design codes, preventative maintenance (RBI, RCM), etc.
7. Random hardware failure, failure modes (including unrevealed unsafe failures), average probability of failure on demand, test intervals and coverage (random failure avoidance: redundancy, diagnostics, etc.), demand modes (infrequent vs continuous)
8. Hazard reduction and layers of protection
9. Risk evaluation models – qualitative vs. quantitative, deterministic vs. stochastic, probabilistic, risk analysis model, developing accident scenarios and initiating events, event trees, risk profiles, consequence determination, uncertainty
10. Risk analysis techniques, process safety analysis, cause and consequence analysis, root cause analysis, bow-tie analysis
11. Advantages and disadvantages of SIL/LOPA studies
12. Organizational safety culture
13. Current state of process safety, machinery safety and key challenges
Legislative and Compliance Framework
1. Typical legislative requirements
2. US OSHA PSM Regulation
3. US EPA / RMP Regulations
4. European Union – Seveso I, II, and III, REACH
5. UK COMAH / CIMAH
6. Norway / North Sea (Safety Case)
7. Australia / New Zealand (Major Hazard Facilities)
8. Australia NOPSEMA (Safety Case)
9. Codes and standards (and exclusions eg, ISO 26262 functional safety of autonomous vehicles, ISO 17757:2017 Earth-moving machinery and mining autonomous and semi-autonomous machine system safety)
10. Safety critical elements and performance standards
IEC 61511 (and IEC 61508) Overview
2. Process risk, residual risk, tolerable risk
3. Separation of process control and process safety
4. Equipment Under Control (EUC) and its application, detection, logic action and safe state definition
5. Safety functions and safety-related systems
6. Safety integrity levels (high and low demand)
7. Systematic capability (refer IEC 61508)
8. Different voting arrangements and their consequences
9. SIL levels, device types and architectural constraints: fault tolerance /redundancy – differences between IEC 61511 and IEC 61508
10. IEC 61511 Clauses 5 and 10.3
11. Safety software requirements – dedicated SRS, V-Model
12. Avoidance of systematic failures and spurious trips
13. Functional safety assessments
14. Functional safety management overview (including planning, verification, validation, functional safety assessment, function testing, management of change, competency and certification) – differences between project personnel and end-user
15. Application of functional safety to process industry and special applications: High Integrity Pressure Protection Systems, Burner Management Systems (ie sequential logic), drilling equipment, batch processes, fire and gas
16. Legacy issues and ‘proven in use’ solutions
AS4024 and IEC/EN 62061 Overview
• Machinery safety overview – use of AS4024 / IEC/EN 62061, standards framework, machinery types
• Safety lifecycle (machine use, hazard identification and risk assessment, SRCF definition, safety requirements specification, design and implementation, testing, installation, validation, maintenance, management of change)
• Safety-Related Control Functions (permissive, protection, mitigation)
• Devices (eg E-stop, guards, light curtains, proximity, two-hand control, safety mats, mechanical switches etc)
• Safety-Related Electrical Control Systems
• Risk assessment example - risk graph and risk matrix
• Protected machinery examples
1. When to conduct SIL studies in relation to other safety studies and level of design maturity
2. Key inputs: risk criteria analysis: calibrating company risk matrices for SIL studies, safety instrumented function identification, HAZAN / HAZOP studies, project documentation
4. Assumptions (eg generally semi-quantitative technique used)
5. Conducting the workshop
7. Independent review
8. Re-analysis during operations
Safety Instrumented Function and Safety-Related Control Functions Design and Verification
1. Identifying SIF and SRCF elements and safe state
2. Reliability block diagrams and fault modelling (FTA, Markov modeling, simplified equations)
3. Failure modes, diagnostic coverage, safe failure fraction, failure data sources & assumptions
4. Proven in use assessment
5. Proof test coverage, preventative maintenance requirements
6. Redundancy and common mode failure
7. Tools and techniques
8. Probability failure on demand calculations examples
Safety Requirements Specification
1. Separation of SIF and non-SIF (and SRCF)
2. SIL determination output and summary
3. Project functional requirements
4. Design basis; scope, context, assumptions, clarifications, definitions, etc.
5. SIF and Safety-Related Control Functions characterization details including: Description, Instances, P&ID, SAFE Chart, Case, Hazardous Event, Causes, Consequences, Process Safety State, Other LOPs Considered, Target SIL, Risk Reduction Factor, Safety-Critical, Demand Mode, Proof Test Interval, MTTFSP, MTTR, Other Special Considerations
Detailed Design Considerations
• Selection of the logic solver hardware supplier for the SIS (and Safety-Related Electrical Control Systems), required components and architecture
• Selection of field devices and other components of the SIS / SRECS
• I/O allocation
• Definition of third-party interfaces (including HMI)
• Calculations (power consumption, heat dissipation, fault current, cable sizing, etc.)
• Prototype testing of typical loops
• Production of drawings to enable the system to be built
• Production of documents and drawings to enable the system to be installed
• Development of project Software Quality Plan
• Selection of software tools and programming language
• Detailed software design (including the definition of program structure, required software modules, communication drivers, diagnostics usage, alarm handling, voting arrangements, overrides, interfaces, etc)
Functional Safety Management
1. Planning – division of responsibility across the safety lifecycle, typical documentation suite
2. FSM plan covering concept, strategy, scope, activities, competency, personnel, roles and responsibilities, organization, independence, processes (ISO 9000 type and FSM specific), planning, documentation, verification and validation plans, monitoring, review and audits
3. Guidance on specific elements: realization, testing, installation, validation, commissioning, formal safety assessment
4. Continual improvement, audit and review, reporting.
Operations and Maintenance
1. Planning and plans for operations
2. Periodic testing procedures (on-line and off-line)
3. Preventative maintenance, field instrumentation and logic solver diagnostics, system alarms)
4. Integration with maintenance management system (PMs, work orders, failure history, backlog management)
5. Managing system integrity, competency, change management
6. System support (expertise, tools, test equipment, spares, repair and test cycle),
7. Optimizing maintenance (failure data, process shutdown capture, data analysis, hazard review, test interval and coverage)
Project and Revision
In the final week students will have an opportunity to review the contents covered so far. Opportunity will be provided for a review of student work and to clarify any outstanding issues. Instructors/facilitators may choose to cover a specialized topic if applicable to that cohort.
The Australian Engineering Stage 1 Competency Standards for the Professional Engineer, approved as of 2013. This table is referenced in the mapping of graduate attributes to learning outcomes and via the learning outcomes to student assessment.
Stage 1 Competencies and Elements of Competency
Knowledge and Skill Base
Comprehensive, theory based understanding of the underpinning natural and physical sciences and the engineering fundamentals applicable to the engineering discipline.
Conceptual understanding of the mathematics, numerical analysis, statistics, and computer and information sciences which underpin the engineering discipline.
In-depth understanding of specialist bodies of knowledge within the engineering discipline
Discernment of knowledge development and research directions within the engineering discipline.
Knowledge of engineering design practice and contextual factors impacting the engineering discipline.
Understanding of the scope, principles, norms, accountabilities and bounds of sustainable engineering practice in the specific discipline.
Engineering Application Ability
Application of established engineering methods to complex engineering problem-solving.
Fluent application of engineering techniques, tools and resources.
Application of systematic engineering synthesis and design processes.
Application of systematic approaches to the conduct and management of engineering projects.
Professional and Personal Attributes
Ethical conduct and professional accountability.
Effective oral and written communication in professional and lay domains.
Creative, innovative and pro-active demeanour.
Professional use and management of information.
Orderly management of self, and professional conduct.
Effective team membership and team leadership.