intro to reliability management
DESCRIPTION
Slides for my presentation in the Hobbs Engineering webinar programTRANSCRIPT
Introduction toReliability Management
Fred SchenkelbergReliability Consultant
(408) 710-8248
What have you done for me lately?
What is your value??
What is your scope?
Or entire industry?
Goals
Estimates
PredictionsTesting
Field
Returns
Goals and Feedback
Specifications
Responses
Score!
Goal!
Back of the Net!
How do you talk about reliability?
As good as or better ….
Make it “reliable”
Do your best.
5 year life
None should ever fail.
www.nomtbf.com
How do those around you talk about reliability?
Four elements
• Function– Primary– Side of box– performance
• Probability– % surviving– Chance of
surviving– No distribution
• Environment– Weather– Stresses– Use profiles
• Duration– Early Life– Warranty period– Useful Life
Practice
• What is the function?
Practice
• What is the environment?
Coffee mug
Practice
• What is the probability and duration?
Practice
• What is another probability and duration?
Brew coffee daily in US home environment 99% reliability over 1 year warranty period and 95% reliability over useful life of 5 years.
System goal of 90% Reliability in 2 years.
Sys
Sub 1 Sub 2 Sub 3 Sub 4 Sub 5
Coffee Machine
Reservoir Heater Plumbing Controls Carafe
97%
Home Coffee Machine95% over 5 years
98% 99% 99% 98%
Sys
Sub 1 Sub 2 Sub 3
Sub 3.1
Sub 3.2
Sub 4 Sub 5
Coffee Machine
Reservoir Heater Plumbing Controls Carafe
97%
Home Coffee Machine95% over 5 years
98% 99% 99% 98%
99% 99% 99% 99% 99%Goals – straight line method
Feedback
• Did you do well?
• Are you on track?
• Corrections?
Concept Design Development ManufacturingField Use
Will
it w
ork?
Will
it w
ork?
Will
it w
ork?
Will
it w
ork?
Did it
wor
k?
Concept
Design
Developme
nt
Manufacturi
ng
Field UseW
ill it
wor
k?W
ill it
wor
k?W
ill it
wor
k?W
ill it
wor
k?Did
it w
ork?
Concept
Design
Developme
nt
Manufacturi
ng
Field Use
FRACAS
Multiple systems
Overbearing Enforcement
Rewards for numbers
Typical early life failuresProduct does not meet design specifications
Material or component characterization
Process characterization
Assembly characterization
Process control – focus on what’s important
Prediction of ELFsNot commonly possibly for unknown variation
Design in some margin
Derating
Safety factor
Determine margin
If variation is know, determine probability of failures – still difficult to know when though.
Hit by a big hammer
Some stress is too large to accommodate
Lightening
Vehicle accident
Meteor strike
Hurricane
Possibly foreseen or expected, and not economical to design the ability to withstand
Prediction of overstress
Not commonly possibly
Design errors
Environment
Unexpected use
When significant adverse consequence may occur explore mitigation or fail safe approaches
Wear out and related
Everything fails – eventually
Understand failure mechanisms and environment
It is a race to cause
the failure
Call Centers
First contact with failure
What do you collect?that is actionable?
What is the main focus?
VALUE
Return on Investment
• Cost or Investment
What do you spend to accomplish the task?
• Return or Benefit
What you realize as a result?
Common to expect at least a 10 to 1 ROI
Given a FET that costs 10 cents, a new procurement engineer finds a new FET vendor that only charges 5 cents.
Switch?
What else to consider?
Given a FET that costs 10 cents, a new procurement engineer finds a new FET vendor that only charges 5 cents.
$0.05 FET has MTBF of 50,000 hours
$0.10 FET has MTBF of 75,000 hours
1000 hours of operationShipping 1000 unitsCost to repair unit $250
Total Cost of $0.10 FET
#Failed = (1-0.987) 1000 units = 13.25
Cost of Repairs = 250*13 = $3250
Total Cost = $3250+0.10*1000 = $3350
987.01000 000,75
1000
10.0
eR
FETCost
RepairCost
TotalCost
$0.10 $325075,000 hrs
$3350
$0.05 $500050,000 hrs
$5050
$0.50 $2500100,000hrs
$3000
How else can we find value?
Summary
• Set goals
• Break goals down
• Create feedback
• Create value
Introduction toReliability Management
Fred SchenkelbergReliability Consultant
(408) 710-8248