Question

Q1: Explain why Engineering Controls (Barriers / Isolation) are more effective than Administrative Controls for reducing accidents? Is this true in ALL cases?

Q2: Is it easier to audit and validate the ongoing safety of a system that uses Engineering Controls than one that uses Administrative Controls?

Q3: How do you identify the candidate components or functions for the an FMEA? How do I know I have ALL the necessary components or Functions?

Q4: Explain why a Preliminary Hazard Analysis (Preliminary Risk Analysis) cannot be used to calculate the overall safety of the design (total likelihood x total consequences)? Does an FMEA solve this problem?

Q5: Should my team use the Severity, Occurrence and Detection table from an industry recommended standard, or should my team generate their own? Does my business manager / my customer need to agree to these tables? Why should I include the Severity, Occurrence and Detection tables in my design document recording the FMEA analysis?

Q6: One of the differences between a Preliminary Hazard Analysis (Preliminary Risk Analysis) and an FMEA is to assess the Detectability of a failure. Why would analysing this lead to a safer / more reliable design?

Q7: "Systems are analyzed to identify their hazards and those hazards are assessed as to their risks for a single reason: to support management decision-making" [NIOSH, 1998]. Name three important management decisions that are 'documented' in the course of performing a fully completed FMEA.

Answer 1

Q1: Explain why Engineering Controls (Barriers / Isolation) are more effective than Administrative Controls for reducing accidents? Is this true in ALL cases?

Ans: To reduce or eliminate exposure to hazards in industries, a system is followed called the Hierarchy of Hazard Control. Th e Engineering Controls and Administrative Controls are both the components of the quoted system.

Engineering Controls don't eliminate hazards, rather isolate workers from hazards.This may include various methods like use of noise dampening technology to reduce noise levels, using mechanical lifting devices, use of local exhaust ventilation that captures the contaminants and carries them away before they get in the breathing zone of workers.

On the other hand, Administrative Controls incorporates changes in workplace policies and procedures like warning alarms, systems for labeling, reduction of hazard exposure time and training and development of workers.

So now it is clear that if we isolate the environment itself instead of making changes into it will be more beneficial in hazard control. That is why Engineering Controls are more effective than Administrative Controls for reducing accidents as worker is not at all exposed to the hazardous environment due to creation of a physical barrier.

Moreover, this is not true in all cases that Engineering Controls are more effective. Let us consider a situation in which workers are not well versed with the procedures and are not properly trained. This may lead to onsite hazard.

Q2: Is it easier to audit and validate the ongoing safety of a system that uses Engineering Controls than one that uses Administrative Controls?

Ans: No, its not easier to audit and validate the ongoing safety of a system in engineering controls. Let us consider the example of a road construction. The road construction in the night time will be treated as the administrative control when fewer people are driving (less people exposed) and hence people are exposed to the environment. So one can audit and validate the ongoing safety of a system. While blocking the traffic till the completion of road construction will be treated as engineering control and in this case no one is exposed to the environment; so on can not audit and validate the safety systems implemented.

Q3: How do you identify the candidate components or functions for the an FMEA? How do I know I have ALL the necessary components or Functions?

Ans: Failure Mode and Effects Analysis (FMEA) is a structured approach for identification of potential failures that can exist within the process or design of a product. A “function” is what the item or process is meant to perform to a available standard requirement. For Design FMEAs, it is the primary purpose or design intent of the item while for the Process FMEAs, it is the primary purpose of the manufacturing operation.

There may be several functions for every item or operation. To identify these functions the FMEA team appraise pertinent documents considering their engineering experience. Moreover,

• FMEA Block Diagram, Parameter Diagram and Functional Block Diagram are used as input to function descriptions for design FMEAs.
• For the Process FMEAs, the Process Flow Diagram and operation work instructions are used as input to the function descriptions.
• In addition, the team can be put up through questions like “what is intended purpose,” or alike questions.

To ensure that all the necessary components and functions are met, we must must prepare "Function Focal Point Table" which is in the following form:

Focus On Function	Description	Intended for the part/process
Basic Function	--------	--------
Additional Function	--------	--------
Unit Function	--------	--------
Harm Prevention Function	--------	--------
Self Protection Function	--------	--------

Q4: Explain why a Preliminary Hazard Analysis (Preliminary Risk Analysis) cannot be used to calculate the overall safety of the design (total likelihood x total consequences)? Does an FMEA solve this problem?

Ans: Preliminary hazard analysis (PHA) is a semi-quantitative analysis which is performed to:

• Identify all potential hazards and hazardous events that may lead to an accident
• Rank the identified hazardous events according to their severity
• Identify required hazard controls and follow-up actions

The reasons due to which Preliminary Hazard Analysis (Preliminary Risk Analysis) cannot be used to calculate the overall safety of the design are as following

a). Hazards must be foreseen by the analysts: In PHA the hazards are predicted or forecasted, hence not exact in level of severity and consequences.

b).The effects of interactions between hazards are not easily recognized.

These issues can be overcome by the use of FMEA in which a structured approach for identification of potential failures that can exist within the process or design of a product is performed and necessary action is taken to eliminate them.