Six Sigma Greenbelt Training FMEA Six Sigma Greenbelt Training Dave Merritt 1-26-17

The Six Sigma Methodology Focus Process Map Y Measurement System Analysis Y Process Capability Y Phase 1: Define/Measure Phase 2: Analyze Graphical Methods X’s Hypothesis Testing X’s Phase 3: Improve Analysis of Variance X’s Design of Experiments Vital Few X’s The analyze and improve phases help you understand your X’s (inputs) and to narrow down to the vital few X’s. Statistical Process Control Vital Few X’s Failure Mode and Effects Analysis Vital Few X’s Phase 4: Control

Learning Objectives Explain the function of an FMEA Demonstrate how to develop an FMEA Review FMEA definitions

What is a FMEA? Failure modes and effects analysis (FMEA) is a step-by-step approach for identifying all possible failures in a product design, a manufacturing process, or a service. “Failure modes” means the ways, or modes, in which something might fail. The Idea… …is to identify ways a failure can occur and then plan to prevent them from occurring.

Purposes and Benefits of FMEA Improves the quality, reliability, and safety of products Increases customer satisfaction Reduces product development timing and cost Documents and tracks actions taken to reduce risk

Types of FMEA’s System FMEA: Used to analyze systems and subsystems in the early concept and design stages. Focuses on potential failure modes associated with the functions of a system that are caused by the design. Design FMEA: Used to analyze products before they are released to production. Process FMEA: Used to analyze manufacturing and assembly processes.

Understanding the Relationships of Causes to Effects A cause can have a one-to-one relationship with an effect Cause 1 Effect 1 Cause 2 Or one cause can have multiple effects Effect 1 Effect 2 Cause 1 The purpose of this slide is to introduce the cause and effect relationship Or multiple causes for one effect Cause 1 Cause 2 Effect 1

Failure Mode Fishbone Model Cause Materials Methods Machine Failure Mode (Defect) However, with an FMEA, the causes link to the Failure Mode which than links to the effect. Effect Human Measurement Environment The causes link to the Failure Mode, which then link to the effect.

Failure Mode Fishbone Model Cause Materials Methods Machine Failure Mode (Defect) Effect Human Measurement Environment The goal of FMEA is to understand your process well enough to anticipate, detect and ultimately prevent the Failure Mode.

Results of a well constructed FMEA List of potential failure modes List of potential critical characteristics List of effects List of causes Documentation of current controls Prioritization of improvement activities Documentation of the history of improvements A starting point for development of control plans

The FMEA Form Lists Failure Modes for Each Process Step

The FMEA Form - Detail List the process steps in sequential order Failure Mode: The manner in which a part/process can fail to meet specification. Usually associated with a defect or non-conformance. Typical Failure Modes: Bent, cracked, deformed, impure, dirty, binding

The FMEA Form - Detail Failure Effect: Impact on customer if Failure Mode is not prevented or corrected. Customer can be downstream or the end user. Typical Failure Effects: (for the end user) Noise, Unstable, Rough, Excessive Effect required Typical Failure Effects: (for the next operation) Cannot fasten, Cannot bore/tap, Does not fit, Does not connect

The FMEA Form - Detail Rates the Severity of each effect to the customer on a scale of 1-10. Severity (SEV): How significant is the impact of the Effect to the customer (internal or external)?

The FMEA Form - Detail Cause: A manufacturing deficiency that results in a Failure Mode. Causes are sources of manufacturing variability associated with Key Process Input Variables. Causes are described in terms of something that can be corrected or can be controlled. Typical failure causes: Improper torque — over, under Improper weld — current, time, pressure Inaccurate gauging Inadequate gating/venting Lists the Causes for each Failure Mode: Each Cause is Associated with an undesired process input.

Occurrence rates how often a particular Cause or Failure Mode Occurs The FMEA Form - Detail Occurrence rates how often a particular Cause or Failure Mode Occurs Current Controls: The mechanisms that prevent or detect the Failure Mode before it reaches your customer. Current Controls include SPC, Inspections, Monitoring, Training, and Preventive Maintenance

The FMEA Form - Detail Detection rates how well the Cause or the Failure Mode can be detected.

Risk Priority Number (RPN) = SEV  OCC  DET The FMEA Form - Detail Risk Priority Number (RPN) = SEV  OCC  DET A reminder: Severity, Occurrence, and Detection are Scored on a 1(Best) to 10 (Worst) Scale. RPN directs priority on corrective action.

Additional FMEA Definitions Critical Characteristics: Items that affect customer safety and/or could result in non-compliance to regulations and thus require controls to ensure 100% compliance. Significant Characteristics: Those items that require SPC and Quality planning to ensure acceptable levels of Quality (Key Process Input Variables).

Severity Ranking

Occurrence and Detection Ranking

Overall FMEA Process Select the Process FMEA team Develop a Process Map and identify all process steps List all the Key Process Outputs to satisfy internal and external customer requirements List Key Process Inputs for each Process Step Rank the inputs according to importance Begin populating the FMEA with the process steps List the associated Failure Modes List the associated Effects for each Failure Mode Assign Severity ranking for each Effect List Potential Causes for each Failure Mode 11. Assign Occurrence rating for each Cause List Current Controls for each Cause Assign Detection ratings to each Cause Calculate the risk priority number for each potential failure mode scenario Establish a Threshold RPN level Determine recommended actions to reduce all RPNs Take appropriate actions Re-calculate all RPNs Make the FMEA a LIVING DOCUMENT! These steps are “as needed” and are completed in an FMEA Worksheet. Next slide

FMEA Worksheet

Class Exercise – 30 minutes - Groups For the process step shown below, begin populating the FMEA Worksheet Pouring a Beer 2. Use the information in the worksheet to populate the FMEA form

Who Prepares a FMEA? The responsible design or process engineer leads the FMEA team The team approach is required! Involve representatives from all affected activities Typical members should include Design, Manufacturing, Assembly, Quality, Reliability, Service, Purchasing, Testing, Supplier, and other subject matter experts as appropriate. Note: The authoring design or process engineer is responsible for making sure the FMEA remains updated. LIVING DOCUMENT!

When is a FMEA Started? When new systems, products, and processes are being designed. When existing designs or processes are being changed. When carry-over designs/processes will be used in new applications, or new environments. After completing a Problem Solving Study (to prevent recurrence of problem). For a Design FMEA, after product functions are defined, but before the design is approved and released to manufacturing. For a Process FMEA, when preliminary drawings of the product are available.

In this session you learned The importance of a FMEA Causes & Effects and how they can be related How a FMEA is constructed and its definitions The importance of the Risk Priority Number (RPN) How a Process Map is used to understand the relationship of key input and output variables When a FMEA is needed and considered complete

Class Exercise – Example