PFMEA error mistake proofing

Question 1

FMEA - what does it stand for?

Answer 1

failure mode effects analysis

Question 2

PFMEA vs. DFMEA

Answer 2

Process / Design

Question 3

what is FMEA?

Answer 3

a step-by-step approach for identifying all possible failures in a design, a manufacturing process, a product, or a service

Question 4

FMEA’s are the foundation for..

Answer 4

for Process Control Plans required by ISO/TS16949

Question 5

“Failure Mode”

Answer 5

the way, or mode, in which something can fail. failures are errors or defects, especially those that affect the customer, and can be potential or actual

Question 6

Effects analysis

Answer 6

• studying the consequences of those failures
• these systems do not assure failure can not occur but provide a structured assessment of risk
• when risk is properly assessed, actions must be implemented to reduce risk to define threshold levels

Question 7

With GM’s current safety recall, which system failed: PFMEA or DFMEA?

Answer 7

DFMEA

Question 8

failures are prioritized according to:

Answer 8

• how serious the consequence of failure (severity)
• how frequently they occur (occurrence)
• likelihood of detection (detection)

Question 9

purpose of FMEA

Answer 9

to take action to eliminate or reduce failures, beginning with the highest-priority failures

Question 10

where did FMEA originate?

Answer 10

originated in the 1940’s by US military. FMEA’s were further developed by the aerospace and automotive industries

Question 11

PFMEA steps

Answer 11

• before developing PFMEA’s, teams should be selected and a process map developed
• list process steps in first column of form
• for each process step, brainstorm a list of potential failure modes (ways in which product/service might fail)
• identify potential effects for each failure mode: rate
• identify potential causes of failure modes and rate likelihood of occurrence
• list controls in place and rate ability of the control to detect the failure mode
• multiply three ratings
• result is Risk Priority Number (RPN) with 1000 as worst case
• identify improvement actions to reduce/eliminate risk associated with high RPN’s
• recalculate RPN, verify RPN is at or below threshold

Question 12

Develop criteria…

Answer 12

tailored to the specific operation for rating the three factors to reduce subjectivity and inconsistency of the rating teams

Question 13

error/mistake proofing

Answer 13

error proof - defect cannot occur

mistake proof - detect can occur but will be detected in station

Question 14

causes of errors/mistakes

Answer 14

4 M’s - man, material, machine, method

Question 15

error proofing

Answer 15

• ideal, this is what you want
• designing a potential failure or cause of failure out of a product or process
• defect cannot occur - prevention

Question 16

mistake proofing

Answer 16

• change to design or process that helps the operator reduce/eliminate defects or prevent defect from continuing downstream
• detection in station

Question 17

error/mistake proofing categories (in order of effectiveness - most effective first)

Answer 17

• error proofing: product/process design
• mistake proofing: control, warning, operational
• detection (out of station) - automated, manual (in zone), manual (after zone)
• procedural: visual aid/procedure

Question 18

Mistake proofing control

Answer 18

• automatically shuts down an operation to prevent defects from continuing in process
• process stopped when defect detected

Question 19

Mistake proofing warning

Answer 19

warning (visible, audible) to the operator of the defect or incorrect process

Question 20

Mistake Proofing Operational

Answer 20

• parts color coded, stamped/marked, or has distinguished feature
• part selection lights
• part presentation

Question 21

Detection: automated vs. manual

Answer 21

• automated: equipment used to detect defects by automated means in next station or after
• manual (in/out of zone): defect by visual means after offending process in and outside of the zone/department

Question 22

Procedural: work instruction/visual aid

Answer 22

visual aid used on work instruction (selecting correct parts, orientation, sequence and example of good vs. bad)

Question 23

Process FMEA

Answer 23

• improves likelihood of designing an error out of a product or process
• reduce defects or detect defects before affecting customer

Question 24

5 why problem solving

Answer 24

reduce problems by root cause analysis with EMP strategies

Question 25

use EMP strategies when..

Answer 25

when suggesting recommended actions for process improvement