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Philips FMEA. Failure Mode and Effect Analysis. Content of the course. Introduction Product - FMEA Blockdiagram , functiontree Process - FMEA Process-flowdiagram (macro-level) , micro-level Facilitatorskills. FMEA-Philips. Introduction. FMEA – Introduction. Why FMEA’s?
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Philips FMEA Failure Mode and Effect Analysis
Content of the course • Introduction • Product - FMEA • Blockdiagram , functiontree • Process - FMEA • Process-flowdiagram (macro-level) , micro-level • Facilitatorskills
FMEA-Philips Introduction FMEA – Introduction • Why FMEA’s? • Definition, Purpose, Types, Benefits • Team Approach
Why FMEA’s? • Appropriate recommended actions may not have been taken. • Savings in engineering time. • Reduction of changes immediately before productionstart (Commercial Release).
FMEA – Definition Structured group of activities which... • Identify potential failure modes • Prioritize actions • Document the process.
FMEA C R (Productionstart) FMEA – Purpose Failures Time
FMEA – Purpose FMEA’s are intended to ... • Rate severity of failure modes • Identify actions to reduce occurence • Test adequacy of controls
FMEA – Types Mechanical Product- FMEA Electrical Optical Mechanical Process- FMEA Electrical Optical
FMEA on EVT Model Mechanical FMEA on First Mechanical Working Model FMEA on Part Files FMEA on chosen Architecture FMEA on Architectures FMEA on L0 Schematics (ftbo L0) FMEA on L0 Board (ftbo L1) FMEA on L1 Board (ftbo L2) Electrical FMEA Sessions
Benefits – Product-FMEA’s Product • Assess failure mode effects on all customers. • Aids in evaluating testspecifications • Evaluation of design relating to DFM DFA DFT • Increases the possibility to detect possible failure modes. Proces
Voordelen – Proces-FMEA’s Design • Assess effects on all customers • Identifies potential manufacturing and assembly causes to focus controls on reducing occurrence or increasing detection. Proces
Generating FMEA’s Who prepares? Who initiates? Who updates? Who is FMEA-customer? When to discard? Failure Mode and Effect Analysis FMEAs Startingdate/revisiondate? How docu-mented? When completed?
Managing FMEA’s FMEA’s are living documents and are updated ... • Modification to a product or process is planned • Component is to be used in new environment • Customer rejections
Core-team FMEA – Team Approach Support-team
Philips Product-FMEA Content Product-FMEA – Content • Define FMEA-team • Define scope • Describe functions • Brainstorming • Function Trees
Facilitator • Representitives from: • development • production • quality • purchase • testdept. • ... Supportteam Design-Enginieer Production/ process-enginieer Core-team Product-FMEA – Team
Product-FMEA – Scope Once coreteam is established ... • Create Blockdiagram • Identify the boundery for Analysis • Confirm composition of support team.
Assembly Service Part X Part Y User Part Z Other systems Blockdiagram Component/Assembly Screw Weld Adhesive
Example blockdiagram (Settop Wildfire) Smartcard PCB Klicked Front Klicked Display PCB Klicked Screwed Screwed Cover Frame PSU
Determine Functions What are the functions of the design? • Describes the intent of the design • Must be measureble or set at an actionable level • Represents all wants, both spoken and unspoken.
Verb Noun Indicates action, occurrence, being Indicates what the action relates to Describe Function Generate Control Display light speed information
Describe Functions Thought starters ... • Satisfy user • Attract user • Guarantee durability • Easy to repare • Safety requirements
Functiontree • Provides an organized approach to identify the essential features of a product • Defines all spoken and unspoken requirements • Provides the team with a clear overview of all the functions of the product.
WHY ? HOW? Second Level Third Level First level Constructing Functiontrees
WHY? HOW? PQR-Cleantest. Tekst clearly visible after x-times cleaning. Must be printable and resistance te wear. Functiontree – Frontbutton (Settop) Display Information
Guidelines • Brainstorm all functions (VERB-NOUN) • Document individual functions by asking “How is this function achieved?” • Repeat left to right, until actionable level • Work right to left and check structure by asking “Why is this function included?”
Product-FMEA – Functions Description Level 1 Description Level 2 Mode of Failure Function Effect Cause Action/ Solution Resp. MC ML P Front Button Tekst clear visible after PQR-test
Potential failure Modes Failure Mode Type Example No function Partial function Not operational Not all of function operating
Failure Modes: Frontbutton Function: Tekst clear visible after 100x cleaning. Failure Mode Type Example No function No tekst available Partial function Tekst partial available
Product-FMEA – Modes of failure Description Level 1 Description Level 2 Mode of Failure Function Effect Cause Action/ Solution Resp. MC ML P Front Button Tekst clear visible after PQR-test Tekst unread-able
Effects failure What are the effects of the failure relating to: - another part - the complete assembly - the customer - the enduser - the governmental regulations
Product-FMEA – Tabel of effects Frontbutton Another part None Complete Assembly Difficult to sale Customer Dissatisfied Enduser Dissatisfied Governmental regulation None Failure Mode Tekst unread-able
Product-FMEA – Effects of failure Description Level 1 Description Level 2 Mode of Failure Function Effect Cause Action/ Solution Resp. MC ML P Front Button Tekst clear visible after PQR-test Tekst unread-able Assembly not possible to sale Customer dissatisfied
Severity (Weightfactor) What is the severity of the effects?
Ratingcriteria voor Severity (Weightfactor) Effect Criteria: Severity of effect Class Non-conforming with safety Safety failure S Correction is nescessary Unacceptable risk A Correctie is recommended Relative big risk B Correctie is usefull Minimum risk C Correctie is nuttig risico C None Accepted failure D
Rating of Weightfactor– example Sev. Part • Frontbutton/ • Tekst readable • after PQR- • test Failure Mode Tekst unreadable Effects Assembly: unsaleable (A) Customer: Dissatisfied (A) Gov.Reg.: None (D) Function A
Product-FMEA – Weightfactor Description Level 1 Description Level 2 Mode of Failure Function Effect Cause Action/ Solution Resp. MC ML P Front Button Tekst clear visible after PQR-test Tekst unread-able Assembly not possible to sale Customer dissatisfied A
Potential Cause of Failure A weakness in the design with a failure mode as effect.
Manufacturing misbuilds Due to design Deficiencies + - + -
Manufacturing misbuilds Robust Design + - + -
Cause of failure Use Fishbone Diagram Tekst on wrong location Tekst unreadable Inkt of poor quality
Cause of failure – “Why”-ladder Tekst unreadable Inkt doesn’t stick Surface roughness not ok. level 1 WHY? level 2 Designrequirement WHY? level 3 WHY?
Effect Could result in Due to Cause Sentencing Technique Failure Mode
Dissatisfied customer Could result in Due to Surface roughness (designreq.) Sentencing Technique - Example Tekst unreadable
Product-FMEA – Cause Description Level 1 Description Level 2 Mode of Failure Function Effect Cause Action/ Solution Resp. MC ML P Front Button Tekst clear visible after PQR-test Tekst unread-able Assembly not possible to sale Customer dissatisfied A Tekst on wrong location
Product-FMEA – Occurrence What is the possibility that the failure occurrs?
Ratingcriteria occurrence Probability of failure Possible Failure Rates Ranking ³ 1 of 3 5 Very high > 1 of 20 4 Moderate 3 > 1 of 400 > 1 of 15000 2 Low < 1 of 15000 1
Product-FMEA – Occurrence Description Level 1 Description Level 2 Mode of Failure Function Effect Cause Action/ Solution Resp. MC ML P Front Button Tekst clear visible after PQR-test Tekst unread-able Assembly not possible to sale Customer dissatisfied 5 A Tekst on wrong location
Produkt-FMEA – Action/Solution What are possible actions to: - eliminate the failure - reduce effect - reduce occurrence.