AIAG-VDA FMEA Process
5
Risk Analysis
6
Optimization
7
Documentation
Risk Analysis
Step 5 of 7 - AIAG-VDA FMEA
Risk Assessment Matrix
Analyze risk based on Severity (S), Occurrence (O), and Detection (D) ratings. Click on cells to view associated failure modes.
S × O
1
2
3
4
5
6
7
8
9
10
10
10
20
30
40
50
60
70
80
90
100
9
9
18
27
36
45
54
63
72
81
90
8
8
16
24
32
40
48
56
64
72
80
7
7
14
21
28
35
42
49
56
63
70
6
6
12
18
24
30
36
42
48
54
60
5
5
10
15
20
25
30
35
40
45
50
4
4
8
12
16
20
24
28
32
36
40
3
3
6
9
12
15
18
21
24
27
30
2
2
4
6
8
10
12
14
16
18
20
1
1
2
3
4
5
6
7
8
9
10
Low Risk (RPN 1-24)
Medium Risk (RPN 25-59)
High Risk (RPN 60-100)
S: Severity, O: Occurrence
Failure Mode Risk Analysis
| Failure Mode | Component |
Severity (S)
|
Occurrence (O)
|
Detection (D)
|
RPN (S×O×D)
|
Risk Level | Actions |
|---|---|---|---|---|---|---|---|
| External fluid leakage | Master Cylinder |
10
|
6
|
4
|
240
|
High |
|
| Brake line rupture | Brake Lines |
10
|
5
|
5
|
250
|
High |
|
| Insufficient pressure generation | Master Cylinder |
9
|
5
|
4
|
180
|
High |
|
| Pressure loss during application | Master Cylinder |
8
|
4
|
6
|
192
|
Medium |
|
| Fluid contamination | Brake Fluid Reservoir |
7
|
6
|
5
|
210
|
Medium |
|
| Restricted fluid intake | Master Cylinder |
6
|
3
|
4
|
72
|
Low |
|
Showing 6 of 6 failure modes
1
Risk Priority Chart
Distribution of Risk Priority Numbers (RPN) across failure modes.
RPN Distribution
Risk Level by Component
High Risk Failure Modes
Critical failure modes requiring immediate attention (RPN ≥ 180).
Critical Risk Items
1
External fluid leakage
RPN: 240
Master Cylinder
Severity:
10
Occurrence:
6
Detection:
4
Fluid loss leading to complete brake system failure. Caused by damaged housing or cracked seals.
2
Brake line rupture
RPN: 250
Brake Lines
Severity:
10
Occurrence:
5
Detection:
5
Complete loss of braking to affected wheels. Caused by corrosion, physical damage, or excessive pressure.
3
Insufficient pressure generation
RPN: 180
Master Cylinder
Severity:
9
Occurrence:
5
Detection:
4
Increased stopping distance, potential accident. Caused by worn internal seals or air in system.
Risk Analysis Guide
Risk Analysis is Step 5 of the AIAG-VDA FMEA process. This step evaluates the risk of each failure mode using three key ratings:
- Severity (S): Impact of the failure
- Occurrence (O): Likelihood of the failure
- Detection (D): Ability to detect the failure
Risk Evaluation
External fluid leakage (Master Cylinder)
10
Low
Medium
High
6
Remote
Moderate
High
4
High
Moderate
Low
S × O × D = RPN
240
Based on RPN value
High
Recommended Actions
Rating Scale Reference
S
Severity Scale
10
Hazardous without warning
7-9
Very high to hazardous
4-6
Moderate to high
1-3
Low to minor
O
Occurrence Scale
10
Very high (≥ 1 in 2)
7-9
High (1 in 8 to 1 in 3)
4-6
Moderate (1 in 80 to 1 in 20)
1-3
Low (≤ 1 in 100)
D
Detection Scale
10
Absolute uncertainty
7-9
Very low to low
4-6
Low to moderate
1-3
High to very high