Functional Safety

2

Determining Validity of Claims and Life Cycle Issues

3

Traditional risk management in mining

• Supplier of equipment incorporates risk controls in supplied plant;

• Asset operator develops operating and isolation procedures;

• Heavy reliance on exclusion and operators detecting abnormal conditions.

4

The introduction of automation

• Introduces new hazards as personnel must approach automated plant to replenish consumables and maintenance

• Methods of isolation more complex (full energy isolation sometimes not an option)

• Mobile plant now has capacity to leave the work area

• No personnel present to detect abnormal conditions Source: RoboMine, JM Chui and JA Meech

University of BC, Vancouver

5

Functional safety standards

• Provide tools/techniques to allow new types of hazards to be identified and managed

• Defines a lifecycle with appropriate activities to maintain level of functional safety

• Provides a means of determining integrity requirements based on risk

6

Functional safety during the operational life requires…

Ongoing evaluation of assumptions made during analysis and design

Critical assessment of component failures

Active monitoring of demands on the safety system

Supporting documentation to be maintained

Well defined operation and maintenance procedures, including repair

Formal proof testing

7

Component failures

Component failure

Is assumed reliability correct?

Are there Environment

Factors?

Compromise SIL

Just replacing unit ineffective

Highlight design assumption

errors

Component suitability

8

Demands

Demand on safety function

Is demand rate as expected?

Was the initiating event considered in

the analysis?

Risk profile incorrect

Hazard identification incomplete

Hazard scenario Not understood

9

Protection layers

Protection Layers

How often are they preventing a demand?

How effective are they?

Risk profile incorrect

Hazard identification incomplete

Hazard scenario Not understood

10

Proof testing

Proof testing

Incomplete test coverage

Proof testing not done to schedule

Reliability compromised

PFD compromised

Dormant dangerous undetected faults

not identified Testing not performed

11

Competency

Functional safety and autonomous technologies introduce additional competency requirements

More than just training……….

Those involved in safety lifecycle activities must be competent by virtue of their education, training and experience.

Underpinning knowledge Behavioral skills

Underpinning Understanding

Technical skills

Competency Types

12

Audits

• Evaluate if planned activities are being performed

• Consider specific activities

• Evaluate if activity being performed as defined

• Does not judge if activity correctly defined

• Ensure planned activities are being performed

• Procedural controls need to be audited

13

Functional safety assessment

• Make a judgment on the level of functional safety achieved

• Can be done after each phase or prior to hazards being present

• Undertaken periodically whilst hazards are present (e.g. for the life of the plant)

• Undertaken by competent persons

• Level of independence required

14

Conclusion

• As we take the next steps in mining automation there will be more obligations on the end user based on design decisions made by the supplier.

• End users need to understand what is required to accept and maintain a functional safety system in order to ensure it is not compromised over time, exposing their personnel to unacceptable risk.

15

Thank you!

Lyn Fernie

Business Manager – Consulting

HIMA Australia Pty Ltd.

Mobile: +61 (0) 438 980 495

Email: Ifernie@hima.com.au