7.11 Types of Risk and Failure Mode and Effects Analysis

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1 Chapter 1: Introduction & CSSBB Exam Strategy

1.1 CSSBB Exam Format, Scoring, and Testing Windows 1.2 Eligibility, Project Affidavits, Application, and Recertification 1.3 Open-Book Strategy, Reference Materials, and a 16-Week Study Plan

2 Chapter 2: Organization-Wide Planning and Deployment

2.1 Fundamentals of Six Sigma and Lean Methodologies 2.2 Selecting the Right Methodology: DMAIC, DFSS, and Lean 2.3 Business Systems, Processes, and Stakeholder Relationships 2.4 Strategic Planning and Deployment of Six Sigma Initiatives 2.5 Six Sigma Roles and Responsibilities 2.6 Organizational Barriers and Common Causes of Six Sigma Failure 2.7 Change Management: Stakeholder Analysis, Readiness, and Communication

3 Chapter 3: Organizational Process Management and Measures

3.1 Impact of Six Sigma Projects on Customers, Suppliers, and Stakeholders 3.2 Benchmarking Types and Performance Goal Setting 3.3 Performance Measures: Balanced Scorecard, KPIs, KBIs, OKRs, and Line of Sight 3.4 Leading and Lagging Indicators and Performance Dashboards 3.5 Financial Measures: Revenue Growth, Margin, NPV, ROI, and Cost-Benefit Analysis 3.6 Cost of Poor Quality and Hard versus Soft Savings

4 Chapter 4: Team Management

4.1 Team Types and Constraints 4.2 Team Roles, Responsibilities, and Member Selection 4.3 Team Success Factors and Ground Rules 4.4 Motivational Techniques and Overcoming Demotivators 4.5 Stages of Team Development and Conflict Resolution 4.6 Team Communication Plans 4.7 Team Leadership Models: Direct, Coach, Support, and Delegate 4.8 Group Behaviors, Conflict Resolution, and Meeting Management 4.9 Facilitation Techniques and Team Decision-Making Methods 4.10 Team Training: Needs Assessment, Delivery, and Evaluation

5 Chapter 5: Define Phase

5.1 Customer Identification and Segmentation 5.2 Customer Data Collection: Methods, Validity, and Reliability 5.3 Customer Requirements: CTX, CTQ Trees, and Operational Definitions 5.4 The Kano Model and Quality Function Deployment 5.5 SIPOC and Process Mapping 5.6 Business Case Justification 5.7 The Project Charter and the Problem Statement 5.8 Project Scope and Boundaries 5.9 SMART Goals and Project Performance Measurements 5.10 Project Charter Reviews and Toll-Gate Governance 5.11 Project Management Tools: Gantt Charts, Toll-Gate Reviews, WBS, and RACI 5.12 Analytical Tools Used Throughout the DMAIC Cycle

6 Chapter 6: Measure Phase

6.1 Process Flow Metrics and the Hidden Factory 6.2 Process Analysis Tools and Value Stream Mapping 6.3 Types of Data and Measurement Scales 6.4 Sampling Concepts, Methods, and Sample Size for Estimation 6.5 Data Collection Plans and Common Pitfalls 6.6 Gage R&R for Variable Measurement Systems 6.7 Attribute Agreement Analysis and Audit MSA 6.8 Measurement Systems Across the Organization, and Metrology 6.9 Population Parameters, Sample Statistics, and Valid Statistical Conclusions 6.10 Descriptive Statistics: Central Tendency, Dispersion, and Shape 6.11 Graphical Methods for Exploratory Data Analysis 6.12 Probability Concepts, Common Distributions, and the Central Limit Theorem 6.13 Additional Distributions: Hypergeometric, Exponential, Lognormal, Weibull, and Bivariate 6.14 Process Capability and Performance Indices 6.15 Capability Studies, Attributes Capability, Yield Metrics, and Long-Term Capability

7 Chapter 7: Analyze Phase

7.1 The Correlation Coefficient, Its Confidence Interval, and Causation 7.2 Linear Regression and Residual Analysis 7.3 Multivariate Tools: Factor Analysis, Discriminant Analysis, and MANOVA 7.4 Hypothesis Testing Terminology, Errors, and Single-Sample Tests 7.5 Statistical Versus Practical Significance 7.6 Sample Size for Hypothesis Tests 7.7 Point Estimates, Confidence, Prediction, and Tolerance Intervals 7.8 Tests for Means, Variances, and Proportions 7.9 Analysis of Variance 7.10 Chi-Square Goodness-of-Fit and Tests of Independence 7.11 Types of Risk and Failure Mode and Effects Analysis 7.12 Gap Analysis and Root Cause Analysis 7.13 Waste Analysis: The Seven Classic Wastes and Resource Under-Utilization

8 Chapter 8: Improve Phase

8.1 Design of Experiments: Objectives, Terminology, and Effects 8.2 DOE Design Principles: Randomization, Blocking, Replication, and Resolution 8.3 Planning and Evaluating Designed Experiments 8.4 One-Factor Experiments: Completely Randomized, Randomized Block, and Latin Square Designs 8.5 Full Factorial Experiments and Design Selection 8.6 Two-Level Fractional Factorial Experiments and Confounding 8.7 Response Surface Methodology and Optimization 8.8 Waste Elimination: Pull Systems, Kanban, 5S, and Poka-Yoke 8.9 Cycle-Time Reduction: Continuous Flow, SMED, and Heijunka 8.10 Kaizen, Kaizen Blitz, Theory of Constraints, and OEE 8.11 Implementation Planning, Piloting, and Solution Selection

9 Chapter 9: Control Phase

9.1 SPC Objectives, Variable Selection, and Rational Subgrouping 9.2 Control Charts for Variables Data 9.3 Control Charts for Attributes Data 9.4 Short-Run SPC and Moving Average Charts 9.5 Control Chart Analysis: Common Cause, Special Cause, and Run Rules 9.6 Total Productive Maintenance and Visual Controls 9.7 Measurement System Reanalysis 9.8 Control Plan Development and Process Owner Handoff 9.9 Lessons Learned, Documentation, and Training for Sustainment 9.10 Ongoing Evaluation of the Improved Process

10 Chapter 10: Design for Six Sigma (DFSS)

10.1 DFSS Frameworks: DMADV, DMADOV, and Design Transfer 10.2 Design for X (DFX) 10.3 Robust Design, Parameter Design, and Verification 10.4 Tolerance Design and Statistical Tolerancing

7.11 Types of Risk and Failure Mode and Effects Analysis

Key Takeaways Explain This Topic AI

The risk types named in the Body of Knowledge are enterprise, operational, supplier, security, product, and cyber-security.

RPN is severity times occurrence times detection, each rated 1 to 10, giving a range of 1 to 1000.

Severity can only be reduced by design change; occurrence by process or design change; detection by improved controls.

Any failure mode with severity of 9 or 10 requires action regardless of its RPN.

DFMEA analyzes failure modes of a product design and is completed before production drawings are released; PFMEA analyzes failure modes of a manufacturing or transactional process.

Last updated: August 2026

Types of risk

The Body of Knowledge asks Black Belts to identify, assess, and prioritize risk at the Analyze level, naming six categories.

Risk type What it covers Typical Six Sigma exposure

Enterprise Strategic, financial, reputational, regulatory risk to the organization A project that changes a validated process, or that touches a regulated claim

Operational Failure of people, processes, or systems in day-to-day execution Process changes, control plan gaps, capacity constraints

Supplier Input quality, delivery, financial viability, single sourcing, geography Tolerance changes passed upstream; sole-source components

Security Physical security, personnel safety, asset protection Changes to access, guarding, or material handling

Product Safety, liability, recall, field performance, warranty Any change to a safety-critical characteristic

Cyber-security Data integrity, availability, confidentiality, connected equipment Changes to MES or SCADA systems, new data flows, IoT sensors

• Assessment is conventionally a two-dimensional judgment of likelihood and impact , plotted on a
• risk matrix, with a third dimension of detectability added in FMEA. Prioritization follows the
• product, and treatment follows the standard four options: avoid (do not do it), mitigate (reduce

likelihood or impact), transfer (insure or contract out), or accept (document and monitor).

• FMEA
• Failure mode and effects analysis is a systematic, bottom-up method for identifying how something can

fail, what happens when it does, why it happens, and what controls exist to catch it.

DFMEA versus PFMEA

• Design FMEA (DFMEA) Process FMEA (PFMEA)
• Subject The product or system design The manufacturing or transactional process

Failure mode A way the design fails to meet its intent A way the process step fails to produce conforming output

Cause Design deficiency: material choice, tolerance stack, geometry Process deficiency: setup, tooling, method, input variation

Timing During design, before production drawings are released for tooling During process design and before launch; revisited at every change

Controls Analysis, simulation, prototype and design verification testing Error-proofing, SPC, inspection, standard work

• Typical owner Design engineering Manufacturing or process engineering
• The timing point is tested: the DFMEA must be complete before production drawings are released for

tooling , because after tooling is committed the cost of a design change escalates sharply.

The rating scales

Each failure mode is rated on three 1-to-10 scales.

Rating Severity (S) -- effect on the customer Occurrence (O) -- likelihood of the cause Detection (D) -- ability of current controls to catch it

• 1 No discernible effect Failure eliminated by design Certain detection; error-proofed
• 2-3 Minor annoyance Very low, isolated High chance of detection
• 4-6 Moderate; customer dissatisfied, some function lost Occasional Moderate chance
• 7-8 High; primary function impaired High, repeated failures Low chance

9-10 Hazardous, or violates a regulation, possibly without warning Very high; failure is almost inevitable Cannot detect, or no control exists

Note that detection is inverted : a high detection rating means poor detection ability. Reversing

this is the single most common FMEA error.

The risk priority number R P N = S × O × D RPN = S \times O \times D RPN = S × O × D

The range is 1 to 1000. RPN ranks failure modes for action, but three rules govern its use:

Severity 9 or 10 requires action regardless of RPN. A safety or regulatory failure mode rated S = 10 S=10 S = 10 , O = 1 O=1 O = 1 , D = 1 D=1 D = 1 has an RPN of 10, which would sit at the bottom of any ranked list, and it still

requires action. Many organizations therefore also compute criticality , S × O S \times O S × O , and screen

on severity first.

• RPN is ordinal, not ratio. An RPN of 200 is not twice as bad as 100, because the underlying
• scales are ordinal. Comparing RPNs across different FMEAs with different rating conventions is

invalid.

RPN gaps are lumpy. Because it is a product of integers, RPN takes only 120 distinct values in

the 1-1000 range, and threshold rules such as "act on everything above 100" create arbitrary cliffs.

Newer practice (including AIAG-VDA) replaces the RPN threshold with an action priority table that

evaluates S, O, and D jointly.

Reducing each component

To reduce You must Example

Severity Change the design or the system so the effect is less harmful Add a mechanical stop so failure cannot injure; fail-safe circuit

Occurrence Change the design or the process so the cause happens less often Error-proof the setup; tighten an upstream tolerance; supplier development

Detection Improve the controls that catch the failure Add SPC on the characteristic; automated vision check; 100% test

• Only a design or system change reduces severity . Adding inspection never reduces severity and never
• reduces occurrence -- it only improves detection. Teams that respond to a high RPN by adding inspection
• are treating the cheapest number to move rather than the risk, and it is the least effective of the
• three. The preference order is always: eliminate the failure mode, then reduce occurrence, then improve

detection.

• The resulting RPN
• The Body of Knowledge is specific on timing: the resulting RPN is calculated after corrective actions
• have been identified and completed . Re-rating before the action is verified records intent, not
• result. In practice the FMEA carries both the initial and the resulting ratings so the effect of the

action is visible.

Worked example

A PFMEA line for a torque-controlled fastening operation:

• Field Entry
• Process step Fasten bracket to housing
• Failure mode Under-torqued fastener
• Effect Bracket loosens in service; potential loss of function
• Severity 8
• Cause Tool calibration drift
• Occurrence 5
• Current control Operator visual check of torque wrench display
• Detection 7
• Initial RPN 8 × 5 × 7 = 280 8 \times 5 \times 7 = 280 8 × 5 × 7 = 280
• Action Torque transducer with automatic reject and 30-day calibration interval
• Resulting O 3
• Resulting D 2
• Resulting RPN 8 × 3 × 2 = 48 8 \times 3 \times 2 = 48 8 × 3 × 2 = 48
• Severity remains 8 because the consequence of an under-torqued fastener in service is unchanged; only a

design change -- for example a self-locking fastener that cannot loosen -- would reduce it.

Running an FMEA well

Do it with a cross-functional team ; a single engineer produces a document, not an analysis.

Work from the process map or design structure , step by step, so nothing is skipped.

Rate against a written, agreed scale , not intuition, or the numbers are not comparable between

team members.

Treat the FMEA as a living document : revisit it at every process change, every new failure mode

found in production, and every customer complaint.

The FMEA's real output is the action list with owners and dates , not the spreadsheet.