Date post: | 13-Apr-2017 |
Category: |
Environment |
Upload: | jing-jing-cheng |
View: | 632 times |
Download: | 1 times |
OCCUPATIONAL SAFETY AND HEALTH (KAS 3501)Course name : Bachelor of Technology
(Environmental)Semester : Year 3 6th SemGroup number : 9Group members :
Presentation Date : 7th April 2015
No.
Name Matric number
1. Nurul Izzaty binti Mohd Walid
UK29520
2. Mohd Syukri bin Abdullah
UK29529
3. Nur Ain Zuriati binti Daud
UK29525
4. Cheng Jing Jing UK295235. Amira Aqilah binti
SafianUK29527
FMEA (Failure mode and effect
analysis)
Simply put an FMEA is:
a process that identifies all the possible types of failures or risk that could happen to a product or process and potential consequences of those failures.
The Failure Mode : what could go wrongThe Effect Analysis : how it would happen;
how likely is it to go wrong; how bad would it be
Background of the FMEA 1940s - First developed by the US military
in 1949 to determine the effect of system and equipment failures
1960s - Adopted and refined by NASA (used in the Apollo Space program)
1970s – Ford Motor Co. introduces FMEA after the Pinto affair. Soon adopted across automotive industry
Today – FMEA used in both manufacturing and service industries
FMEA:• Commonly used in a variety of industries for Risk
Management• One of the most useful and effective tools for
developing designs, processes and services
• Goals of FMEA: To align risk as closely as possible with its source
• This enables: the determination of the root causes of the risk allow the selection of ways to detect the
occurrence/probability of a particular failure find options to prevent/mitigate the effects of a
particular failure
It is important to know why we would do an FMEA.
It is for procedures or inventions that would be very risky or very expensive.
We want to prevent problems before they happen and that is exactly what an FMEA does.
Doing an FMEA is imperative to making sure things run smoothly.
HINTS: Preventing problems is cheaper and easier than
cleaning them up. Some things are too risky or costly to incur mistakes.
The Reasons for FMEA Get it right the first time Indentifies any inadequacies in the
development of the product Tests and trials may be limited to a few
products Regulatory reasons Continuous improvement Preventive approach Team building Required procedures
FMEA provides the potential to: Reduce the likelihood of customer complaints Reduce the likelihood of campaign changes Reduce maintenance and warranty costs Reduce the possibility of safety failures Reduce the possibility of extended life or
reliability failures Reduce the likelihood of product liability
claims
FMEA is a Team ProcessTeam Formation Product Development Design Manufacturing Quality Sales/Marketing Suppliers Reliability and testing
Team Roles Facilitator Champion Recorder/librarian 6-10 members is optimal
When to use FMEA IMPROVE
- When a process, product or service is being designed or redesigned, after quality function development- When existing product is applied in a new way- Before developing control plans for a new or modified process.- When improvement goals are planned for an existing process, product or service.
When to use FMEA ANALYSE
- When analyzing failures of an existing process, product or service.- Periodically throughout the life cycle of the process, product or service.
Types of FMEA
FMEA
Design FMEA
System
Sub-System
Component
Process FMEA
Assembly
System
Sub-System
Component
Manufacturing
System
Sub-System
Component
Process FMEA Analyze manufacturing and assembly
processes at the system, sub-system or component levels
Focuses on potential failure modes of the process that are caused by manufacturing or assembly process deficiencies
Commonly used in regard to patient care, especially associated with certain types of surgery
Commonly used in many industries to access certain process involved in providing customer care.
Potential failures: operator assembling part incorrectly, excess variation in process resulting in out spec products
Example: Air Bag Assembly Process (operator may not install air bag properly on assembly line such that it may not engage during impact)
Design FMEA Used to analyze products before produce Examine the function of a system, sub-system
or component Focuses on potential modes of products
caused by design deficiencies Done at three levels-system, sub-system and
component levels Analyze hardware, functions or a combination
Potential failures: incorrect material choice, inappropriate specification
Example: Air Bag (excessive air bag inflator force)
BENEFITS OF FMEA Improve product/process quality, reliability
and safety Reduce development time Early identification and elimination of
potential product/process failure modes Prevent failure before they happen. Identifies critical aspect of design and process
LIMITATIONS OF FMEA Examinations of human error is limited Examinations of external influences is limited Results are depended on the mode of
operations.
FMEA Procedure1. Assemble a cross-functional team
of people with diverse knowledge about the process, product or service and customer needs.
Functions often included are: design, manufacturing, quality, testing, reliability, maintenance, purchasing (and suppliers), sales, marketing (and customers) and customer service.
FMEA Procedure
2. Identify the scope of the FMEA :- Is it for concept, system, design, process or service?
- What are the boundaries? - How detailed should we be?
Use flowcharts to identify the scope and to make sure every team member understands it in detail.
FMEA Procedure
3. Fill in the identifying information at the top of your FMEA form.
Figure 1 shows a typical format. The remaining steps ask for information that will go into the columns of the form.
FMEA FORM
Figure 1: Typical format of FMEA
FMEA Procedure
4. Identify the functions of your scope :-What is the purpose of this system, design, process or service?
In the form, name it with a verb followed by a noun. Usually you will break the scope into separate subsystems, items, parts, assemblies or process steps and identify the function of each.
Item/ Process function
• Briefly outline function, step or item being analysed• Be specific• For example, part of a machine such as pump or oil filter
FMEA Procedure
5. For each function, identify all the ways failure could happen.
These are potential failure modes.How does the item or process fail to meet specifications or purpose of design?If necessary, go back and rewrite the function with more detail to be sure the failure modes show a loss of that function.
Potential Failure Mode
• Identify failure modes. (Hazard analysis)• A failure mode is defined as the manner in which a component, subsystem, system or process could potentially fail to meet the design intent
FMEA Procedure
6. For each failure mode, identify all the consequences on the system, related systems, process, related processes, product, service, customer or regulations.
These are potential effects of failure.
Potential Effect(s) of Failure
• List out all the possible effects of the failure.• For example, reduced performance, potential risk and injury
FMEA Procedure
7. Determine how serious each effect is.
• This is the severity rating, or S. • Severity is usually rated on a scale from
1 to 10, where 1 is insignificant and 10 is catastrophic.
• All effects should be rated although rating of severity is based on the most severe effect.
Severity •Determine the severity of the failure effects on a scale of 1- 10• All effects should be rated• If severity is based upon criteria or standard, rating tables should be included with the analysis.
Table 1: Examples of severity rating table
FMEA Procedure8. Is this failure mode associated with a
critical characteristic?
• Usually, critical characteristics have a severity of 9 or 10 and occurrence and detection ratings above 3.
• Examples of critical characteristics include dimensions, specifications, tests, assembly sequences, tooling, joints, torques, welds, attachments, and component usages.
• Special actions or controls necessary to meet these requirements may involve manufacturing, assembly, a supplier, shipping, monitoring, or inspection.
Classification
• Classification is used to define the critical characteristics (product or process requirements that affect safety or compliance with government regulations and require special controls)• ‘Y’ or ‘N’ will be filled in the Classification column to show whether special controls are needed.
FMEA Procedure
9. For each failure mode, determine all the potential root causes.
• Use tools classified as cause analysis tool, as well as the best knowledge and experience of the team.
• List all possible causes for each failure mode on the FMEA form.
Potential Cause(s) / Mechanism(s) of Failure
•For each failure mode, determine and list all the potential root causes
FMEA Procedure
10. For each cause, determine the occurrence rating, or O.
• This rating estimates the probability of failure occurring for that reason during the lifetime of your scope.
• Occurrence is usually rated on a scale from 1 to 10, where 1 is extremely unlikely and 10 is inevitable.
• On the FMEA table, list the occurrence rating for each cause.
Occurrence• For each cause, determine the occurrence rating.• This rating estimates the probability of failure occurring• Occurrence is usually rated on a scale from 1 to 10, where 1 is extremely unlikely and 10 is inevitable
FMEA Procedure
11. For each cause, identify current process controls.
Current process control• Identify current process controls. • These are tests, procedures or mechanisms that now keep failures from reaching people involved such as employee. • These controls might prevent the cause from happening, reduce the likelihood that it will happen or detect failure after the cause has already happened
FMEA Procedure
12. For each control, determine the detection rating, or D.
• Detection is usually rated on a scale from 1 to 10, where 1 means the control is absolutely certain to detect the problem and 10 means the control is certain not to detect the problem (or no control exists).
• On the FMEA table, list the detection rating for each cause.
Detectability• Determine the detection rating for each control.• This rating estimates how well the controls can detect either the cause or its failure mode after they have happened but before people is affected. • Detection is usually rated on a scale from 1 to 10
FMEA Procedure
13. Calculate the risk priority number, or RPN, which equals S × O × D.
• Also calculate Criticality by multiplying severity by occurrence
, S × O. • Lowest detection rating is used to calculate RPN• These numbers provide guidance for ranking
potential failures in the order they should be addressed.
RPN (Risk Priority Number)
• RPN = Severity × Occurrence × Detection• These numbers provide guidance for identifying items which required attention and assign a priority to them.
FMEA Procedure
14. Identify recommended actions.
Recommended Action(s)
• Identify recommended actions. • These actions may be design or process changes to lower severity or occurrence. • They may be additional controls to improve detection.
Responsibility and Target Completion Date
• List out the name of people who is responsible for the actions• The date by which the action(s) need to be taken
FMEA Procedure15. As actions are completed, note result
and the date on the FMEA form. Also, update new S, O or D ratings and new RPNs to reflect actions taken.
Unless the failure mode has been eliminated, severity should not change
Occurrence may or may not be lowered based upon the results of actions
Detection may or may not be lowered based upon the results of actions
If severity, occurrence or detection ratings are not improved, additional recommended actions defined
Action(s) Taken
• Remedial actions taken must be listed out in details
Severity, Occurrence, Detectability, RPN
As actions are completed, new Severity, Occurrence and Detectability ratings and new RPNs are determined.
Example of FMEA form
Prevention is better than cure.
References Benefits of FMEA. (n.d.). Retrieved from:
http://a-anai.com/FMEA_benefits.htm Failure Mode Effects Analysis (FMEA). (n.d.) . Retrieved from:
http://asq.org/learn-about-quality/process-analysis-tools/overview/fmea.html
FMEA-FMECA, Your Guide for FMEA Information and Resources Retrieved from: http://www.fmea-fmeca.com/types-of-fmea.html
Friend, M. A., John, J. P. (2007). Fundamentals of Occupational Safety and Health. UK: Government Institutes.
Nancy R. Tague’s, The Quality Toolbox, Second Edition, ASQ Quality Press, 2004, pages 236–240.
University of Ljubljana. (2009). Failure Mode and Effects (and Criticality) Analysis Fault Tree Analysis. Retrieved from: http://lrss.fri.uni-lj.si/sl/teaching/rzd/tutorials/slovak2010_FMEA_FTA.pdf
Thank You