EMT 480 Reliability Failure Analysi s Failure Modes

EMT 480 Reliability & Failure Analysi s Failure Modes Effect Analysis (FME A)

Learning Objectives �To understand the use of Failure Modes Effect Analysis (FMEA) �To learn the steps to developing FMEAs �To summari thediffere type of FMEA ze 2 nt s s

Benefits �Allows us to identify areas of our process that most impact our customers �Helps us how our process is most likely identify to fail � to proce failure tha ar mos difficul to dete Points ss s t e t t ct 3

Application Examples � Manufacturing: A manager is responsible for moving � a manufacturing operation to a new facility. He/she wants to be sure the move goes as smoothly as possible and that there are no surprises. Design: A design engineer wants to think of all the possible ways product being designed could fail so that robustness can be built into the product. � Software: A software engineer wants to think of possible problems a software product could fail when scaled up to large databases. This is a core issue for the Internet. 4 a

What is Failure Mode and Effects Analysis (FMEA)? �For electronic systems, FMEA is the common method for assessing and improving reliability based on failure analysis. �Main objective of FMEA is to identify the potential failure modes of the components contained in the system under analysis and their the possible frequentl occu effects an ho their consequences on system performance. y y r d w are, the how �Iteasily also aims to prioritise the failures according to they can be how serious detected. 5

Examples History of FMEA industry during Aerospace the Apollo �In 1974, themissions Navy developed MIL-STD-1629 regarding the use of FMEA by �In the late 1970’s, the automotive industry was driven liability costs to use FMEA �Later, the automotive industry saw the advantages of using this tool to reduce risks related to poor quality �First used in the 1960’s in the 6

What Can Go Wrong? What Is A Failure Mode? �A Failure Mode is: �The way in which the component, subassembly, product, input, or process could fail to perform its intended functionmay be the result of operatio or �Failure modes upstream may cause downstream to fail ns operations �Thing tha coul gowron s t d g 7

FMEA 8 � Why �Methodology that facilitates process improvement �Identifies and eliminates concerns early in the development a process or design �Improve internal and external customer satisfaction �Focuses on prevention �FMEA may be a customer requirement (likely contractual) �FMEA may be required by an applicable Quality Management System Standard (possibly ISO) of

FME A �A structured approach to: �Identifying the ways in which a product or �process can fail �Estimating risk associated with specific causes the actions that (desig should. FMEA be taken to �Prioritizing Evaluating design or curren reduce riskplan validation ) t contro pla (proce FMEA n l n ss ) 9

When to Conduct an FMEA �Early in the process improvement investigation �When new systems, products, and bein g processes are �When existing designs or processes are being designed changed �When carry-over designs are used in new applications �After system, product, or process functions are defined, but before specific hardware is selected or released to manufacturing 10

A Closer Look The. FME Form A Identify failure modes and their effects 11 Identify causes of the failure modes and controls Prioritize Determine and assess actions

Specialized Uses Types of FMEAs �Design �Analyzes product design before release to production, with a focus on product function �Analyzes systems and subsystems in early concept and design stages �Process �Used to analyze manufacturing after they are implemented 12 an assem process d bly es

SYTEM – focuses on global system function SERVICE – focus on service function. SOFTWARE – focus on software functions

Types of FMEA

Team Input Required FMEA: A Team Tool �A team approach is necessary. �Team should be led by the Process Owner who is the responsible manufacturing engineer or technical person, or other similar individual familiar with FMEA. �The following b considered for member should e team– Operato s: – Design – Engineers – Process Engineers – Materials Suppliers Customers 13 – rs – Reliabilit y Supplier s

Process Steps FMEA Procedure 1. For process input (start with high value inputs), each the 2. ways determine in which the input can go wrong (failure mode) �Select a severity level for each effect (ie scratch, crack, contaminate etc)mode, determine effects For failure 3. each Identify potential causes of each failure mode �Select an occurrence level for each cause (ie handling, 4. machine problem) List current controls for each cause �Select a detection level for each cause (ie provide training, maintenance of the machine) 14

Process Steps FMEA Procedure (Cont. ) 5. Calculate the Risk Priority Number (RPN) 6. Develop recommended actions, assign responsible persons, and take actions (ie thorough inspection to the problem machine) �Give priority to high RPNs �MUST look at severities rated a 10 7. Assign the severity, occurrence, detectio level predicted n s an compar RPN and d e s 15

Severity, Occurrence, and Detection Analyzing Failure & Effects � Severity �Importance of the effect on requireme nts to 10 customer Can be assigned from 1 (no danger) � (critical) � Occurrence from � The causes and frequencies of all possible failures (obtain past data if possible) �Can be assigned from 1 (low) to 10 (extremely high) 16 � Detection (then prevent) for a given cause (may be difficult �The ability of the current control scheme to to estimate detect early in process operations).

Risk Priority Number (RPN) � RPN Calculating a Composite Score is the product of the severity, occurrence, and detection scores. �The highest RPN is 10 x 10 = 1000, which indicates that the failure is very severe, that occurrence is almost certain and it. X Occurren X Detecti = RP Severit is not ceby inspectionon N y detectable 17

It is the name of the component which is analyzed

Identifies the name and ID of the systems or subsystems

Contains names of the responsible individuals that have the authority to perform task

Identifies the team responsible for this design

Used for document tracking purposes

Contains the original date and revised date

Contains the name and Id of item being analyzed as well as one specific function of the item

Contains methods 1. May fail to meet design criteria 2. May cause potential failure in high level systems and low level system

Severity(S)

Used to specify any additional controls

Reasons for failure

Occurrence(O)

Prevention measures

Risk priority number(RPN)=S*O*D

Corrective actions examined by the team

Target completion dates

After an action has been taken, the actual action and the effective date should be entered in this colums

Key Points Summary �An FMEA: �Identifies the ways in which a product or fail process can �Prioritizes Estimates theactions risk associated with specific that should to reduc risk � causes be taken e �FMEA a team tooltype of FMEA differe �Thereisare two nt s s: �Design � Process 18