AGENDA Day 1
Introductions
Background information - Robert Hoffmann
Objectives
Introduction to Design FMEA
Understand the system
-
Diagrams
Functions
P – Diagrams
Design FMEA –Functions, Failure Mode, Effects,
Causes, Controls(for failure modes and causes)
THEME
Day 1
Connector  Design
Terminal and Wire assembly  Design
Wire striped ready  Design
Day 2
Prepare wire  Process
Terminal assembly to wire Process
Assemble wires to connector Process
System Name:
Wiring Connector
Understand the system
Diagram or drawing of system
Hierarchy Diagram
Boundary Diagram
Functions
Function Tree
Highest Measurable Function
Functional interface diagrams
System Targets
Transfer function
Ideal Output
Error states
'P' Diagram
System Noises
Range of system noises
Effect of system noise on ideal output
Interface Targets
Sub-system Targets
Hierarchy Diagram System Name:
Wiring Connector
VEHICLE
Engine
Wiring
Loom
POWERTRAIN
CHASSIS
ELECTRICS
Powertrain
Control
Module
Vehicle
Wiring
Loom
Wiring
Connector
assy
(Male)
BODY
Engine
Cooling
Wiring
Connector
assy
Female
(Male)
Wire with
Terminals
(Male)
Connector
Housing
(Male)
Wire with
Terminals
(Female )
Wiring
Terminal
(Male)
Wire
Assembly
Wiring
Terminal
(Female)
Wire
strands
Wire
Cover
Connector
Housing
(Female)
Exhaust
System
Boundary Diagram System Name:
Throttle
Body
Throttle
Position
Sensor
Engine
Vibration
Wiring Connector
Other
parameter
condition
sensors
Engine
compartment
body panel
Wire and
Connector
(3 Wires)
Engine
Movement
Wire and
Connector
(3 Wires)
Under bonnet
Temperature
Idle speed
control
Valve
Engine
Control
Module
Under bonnet
Humidity
System Boundary
Functions System Name:
Wiring Connector
What does the 'Wiring Connector' do?
Brainstorm
Conduct Electricity
Connect Wires
Insulate Terminals
Function Tree
System Name:
Function
1. Conduct Electricity How?
1.1. Connect Wires How?
Wiring Connector
Measure
1.1.1. Restrain Wiring loom
Pull off load
1.1.2. Position Terminals (axially)
Spacing
1.1.3. Contact Mating Terminal
Surface area
1.1.4. Retain Mating Connector
Pull apart load
2. Insulate Wires How?
2.1.
Insulate Terminals How?
2.1.1. Separate Terminals
2.1.2.
(with insulating material)
Cover Terminals (with insulating material)
Thickness / Area
Resistance
Thickness / Area
Resistance
How does the wire with terminal support the
Wiring Connector System Functions?
Function Tree
System Name:
Wire with Terminal
Function
1. Conduct Electricity How? .
1.1.
Connect Wires How? .
Measure
1.1.1. Position Terminals (lengthwise)
Distance
1.1.2. Crimp Wire (at wire to terminal interface)
Profile /
Pull off Force
1.1.3. Squeeze Terminal
Interference
/ Push in force
(at terminal to terminal interface)
2. Insulate Wires How?
2.1.1. Restrain Wire Insulation Sleeve (Crimp Sleeve) Pull off load
How does the Wire Assembly support the Wiring Connector
System Functions and the wire with terminal Sub-system
Functions?
Function Tree
System Name:
Wire Assembly
Function
Measure
1. Conduct Electrical current How? .
1.1. Allow Wire Crimping How? .
1.1.1. Bare Crimp Surface (ready for crimping)
Contact Area
1.1.2. Position Wire End
(ready for crimping)
Wire Length
2. Insulate Wires How? .
2.1.
Cover Wires
(with insulating material)
2.2 Minimise Bare Wire
(to allow crimping)
Thickness /
Resistance
Length of Bare Wire
When completing a design FMEA the following secondary functions should be
considered.
Has any corporate or regulatory target been set?
Has a program specific target been set?
Has a design feature specifically been created to satisfy the potential secondary
function?
Should there be a design feature to satisfy the requirement?
Do not try to make a feature fit these requirements.
POTENTIAL SECONDARY FUNCTIONS
1.
2.
Perform Safely
Perform transparently (to occupants)
2.1. Perform without physical discomfort
2.2. Drive acceptably
3. Assemble Easily
4. Ease Service ability
5. Prevent Tampering
6. Prevent Unauthorised Access
7. Feel Secure
8. Satisfy occupant ergonomics
9. Ease Recycleability
10. Ease Traceability
11. Achieve Electro-Magnetic Compatibility (EMC)
12. Achieve acceptable craftsmanship standards
13. Achieve acceptable underhood tidiness standards
14. Achieve acceptable NVH standards
14.1.Be free from ‘Squeak and Rattle’
14.2.Achieve acceptable sound quality
15. Achieve acceptable crashworthiness
16. Minimise environmental impact
17. Avoid System interactions
Functional interface diagrams
System Name: Wiring Connector (both Parts)
Connection
Current
Conduct Electricity
Connect Wires
Contact Mating Terminal
Terminal
Wire
Terminal
Conduct Electricity
Connect Wires
Position Terminals
(axially)
Conduct Electricity
Connect Wires
Position Terminals
(axially)
Insulate Wires
Insulate Terminals
Separate Terminals
Conduct Electricity
Connect Wires
Restrain Wiring loom
Insulate Wires
Insulate Terminals
Separate
Terminals
Connector
Insulate Wires
Insulate Terminals
Cover Terminals
Insulate Wires
Insulate Terminals
Cover Terminals
EARTHING
Wiring Connector (both Parts) SURFACE
1
System Target ◇
Conduct Electricity
-------
Conduct Electricity
Connect Wires
Restrain Wiring loom
Connector
Conduct Electricity
Connect Wires
Retain Mating Connector
EARTHING
System
Targets System Name:
SURFACE
Wire
0 to 5V at xx Amps
Continuously when requested
Max % voltage error = x %
Underbonnet temperature range
–400C to +1600C ?
System Requirements to meet target
Connect Wires by
Restraining Wiring loom
Positioning Terminals (axially)
Contacting Mating Terminal
Retaining Mating Connector
xN
x by y mm
x mm2
and x mm
xN
Pull off load
Spacing
Surface area
Interference
Pull-apart load
△
System Target 2
Insulate Wires
--------
Min xxx resistance
Continuously
Underbonnet temperature range
Humidity range ------
–400C to +1600C
System Requirements to meet target
Insulate Terminals by
Separating Terminals
Covering Terminals
x mm Insulation Thickness over entire area
with xx  Resistance
x mm Insulation Thickness over entire area
with xx  Resistance
Date:
Error States
Description
Wiring Connector FMEA
Low Voltage
High Voltage
Oscillating Voltage
Heat
Function:
.
Conduct Electricity…
Input
Description
Applied Signal
V
Function
Ideal Output
Units
Description: -
Description
V
Conduct electricity
Transfer Function
Received Signal
Units
V
V
.
Noise Factors
Piece to Piece Variation
Pin to socket interference
Connector pull apart load
Crimping contact area
Wear Out
Pin to socket wear
Corrosion of wire in terminal
Connector retention
feature…wear out
Human influences & Duty cycle
Long journeys heating
the…underhood air
Fiddling with wires
Water and Mud splash routes
External Environment
Humidity of surrounding air
Ambient Air temperature
System Interactions
Engine rock (wire stretch)
Fixing to body (Strain on
terminals)
Control Factors
AGENDA Day 2
Connections with yesterday
Questions
Review Objectives
Introduction to Process FMEA
Understand the Process
-
Diagrams
Functions: - Process Step, Purpose, Requirements
Design FMEA –Functions, Failure Mode, Effects,
Causes, Controls (for failure mode and causes)
THEME
Day 1
Connector  Design
Terminal and Wire assembly  Design
Wire stripped ready  Design
Day 2
Prepare wire  Process
Terminal assembly to wire Process
Assemble wires to connector Process
PROCESS
FMEA
PROCESS FLOW DIAGRAM
OPERATION:
Prepare Wire for Crimping
1. Cut
2. Strip
3.
Wire to
length
Wire
& Identify
1.1
Unreel Wire
from drum
2.1 Transfer
cut wire to
stripper
3.1 Measure
whole length
& strip lengths
1.2
Place wire in
cutting jig
2.2 Locate &
hold wire in
stripper jig
3.2
Discard rejects
1.3
Cut wire to
length
2.3 Strip
Wire bare to
end of wire
3.3 Place OK
parts in
container
1.4
Unload wire
from tooling
2.4 Rotate to
present other
end of wire
3.3 Check
container has
identity marked
Measure
Wire
2.5 Strip
Wire bare to
end of wire
PROCESS
FMEA
PROCESS FLOW DIAGRAM
OPERATION: Crimp Terminals onto wire
1. Load
terminals
& wire
2. Crimp
terminals to wire
Measure Crimp
& Identify Wire
3.
1.1 Select
terminal for
crimping
2.1 Hold
wire Steady
3.1 Measure
crimp
integrity
1.2 Place
terminal
in Jig
2.2 Carry out
crimping op
3.2
Discard rejects
1.3 Unload
Wire from
container
2.3 Rotate to
present other
end of wire
3.3 Place OK
parts in
container
1.4 Place
Wire in
crimping jig
2.4 Carry out
crimping op
3.3 Check
container has
identity marked
2.5 Unload
wire from
tooling
PROCESS
FMEA
PROCESS FLOW DIAGRAM
OPERATION: Assemble wires to Connector
1. Load
wires to
assembly jig
2. Assemble
3. Fasten Connector
Connector parts
to wire & terminal
1.1
2.1
3.1
1.2
2.2
3.2
1.3
2.3
3.3
1.4
2.4
3.3
2.5
Functions for Process FMEA
For Process FMEA the Function is to complete the step whilst achieving all the requirements set to
achieve the design target.
Step Number
Purpose
Requirements
1. Cut Wire to length
1.1.
Unreel wire from drum
To supply wire for loom
Wire aligned with jig
Sufficient wire on roll
Wire can be gripped by tooling.
1.2.
Place wire in cutting Jig
To be aligned for cut
Wire square to cutter
No dirt or grease on surface
1.3.
Cut wire to length
Have length to suit loom
Correct Length within tolerance
Square Cut
No damage to sleeve
1.4.
Unload wire from tooling To transfer to next op
2. Strip Wire
2.1. Transfer cut wire to
Be ready for stripping
Transfer without damage
or contamination
Locate & hold
wire in stripper jig
Ensure wire in correct
position
Wire end in correct location
Wire does not slip if pulled
No damage to sleeve
Strip Wire bare
to end of wire
To allow electrical
conduction to terminal
when crimped
Correct Length within tolerance
is stripped
No insulation remains in stripped area
Core wire not damaged
stripper
2.2.
2.3.
Wire removed from cutting area
No damage to sleeve
2.4.
Rotate to present
other end of wire
To allow other end
to be stripped
Rotate without damage
or contamination
To allow next op
No damage to sleeve
Core wire not damaged
2.5. as 2.3.
2.6.
Unload wire
from tooling