ME508

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.

Learning Outcomes

On successful completion of this subject/unit, students are expected to be able to:
     

1. Judge applicable regulations, international standards and risk identification processes.
   Bloom’s Level 5.
2. Participate in and make a valuable contribution to safety studies and set safety targets for Safety Instrumented Systems.
   Bloom’s Level 5
3.  Plan and execute Safety Instrumented Systems projects in accordance with the safety life cycle requirements of internationally recognized standards.
   Bloom’s Level 6.
4. Verify and assure Safety Instrumented Systems performance across the safety life cycle in accordance with internationally recognized standards.
   Bloom’s Level 5.
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.

Student assessment

Prescribed and Recommended Readings

Required textbook

• 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

Reference Materials
Number of peer-reviewed journals and websites (advised during lectures). Some examples are listed below.

1. Engineering standard: IEC 61508:2010 Functional Safety of Electrical/ Electronic/ Programmable Electronic Safety-related Systems (E/E/PE, or E/E/PES).
2. Engineering standard: IEC 61511:2004 Functional Safety - Safety instrumented systems for the process industry sector.
3. Engineering Standard: IEC/EN 62061:2006 Safety of machinery: Functional safety of electrical, electronic and programmable electronic control systems.
4.  Engineering Standard: AS 4024.1:2014, Safety of Machinery.
5.  IDC notes and Reference texts as advised.
6. Other material advised during the lectures.

Unit Content

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

Topic 3

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

Topic 4

IEC 61511 (and IEC 61508) Overview

1. Process risk, residual risk, tolerable risk
2. Separation of process control and process safety
3. Equipment Under Control (EUC) and its application, detection, logic action and safe state definition
4. Safety functions and safety-related systems
5. Safety integrity levels (high and low demand)
6. Systematic capability (refer IEC 61508)
7. Different voting arrangements and their consequences
8. SIL levels, device types and architectural constraints: fault tolerance /redundancy – differences between IEC 61511 and IEC 61508
9. IEC 61511 Clauses 5 and 10.3
10. Functional safety assessments
11. 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

Topic 5

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

Topic 6

SIL Studies

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
3. Attendees
4. Assumptions (eg generally semi-quantitative technique used)
5. Conducting the workshop
6. Reporting
7. Independent review
8. Re-analysis during operations

Topic 7

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

Topic 8

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

Topic 9

Detailed Design Considerations

1. Hardware
• 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

2. Software
• 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)

Topic 10

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.

Topic 11

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)
8. Decommissioning.

Topic 12

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.

Engineers Australia

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.

Software/Hardware Used

Software

• Software: Open PHA™ – Kenexis

• Version: N/A

• Instructions:  N/A

• Additional resources or files: N/A

Hardware

• N/A

Unit Changes Based on Student Feedback