FMEA - Failure Modes and Effects Analysis

FMEA - Failure Modes and Effects Analysis

The main goal of the FMEA (Failure Mode and Effect Analysis) is to prevent failures. Therefor it belongs to the important tools of the quality planning. It is assumed that the general meaning is known.

iQ-FMEA has been developed under various aspects:

the system has to meet the practical requirements according to the VDA series of publications

it has to support the structured process of FMEA sessions through algorithms, tables and methods the history of a FMEA is to be shown for every step of improvement

experiences (knowledge base) of previous FMEAs have to be able to enter in current FMEAs. Therefor certain parts of a FMEA are emphasized as standard. They are independent of the current product or process.

employees without a lot of knowledge about information processing have also be able to use the FMEA

FMEA header, that contains general information for the most common standard forms FMEA versions; each version describes a segment of the FMEA-development

system elements as units for analysis functions of a system element possible malfunctions of a function integrated knowledge base

extensive provisions for action management

The structure elements in detail

FMEA header

FMEA id and short description FMEA type

method of evaluation material

drawings

initial part/process or optimization analysis extensive text description

entire status of the FMEA

Version

FMEA can have several versions.

One version describes the FMEA progress from the realisation of corrective actions to the recommendation of further actions. A new version closes the predecessor.

cost input after each session; time and money investments in persons; direct costs cost cumulation over all sessions of a version and over the whole period of a FMEA divers further management data on version level

System elements (SE)

any number of system elements in a version

assignment of a system element to a SE class. This makes it possible to define arbitrarily structured search criteria (knowledge base).

SEs can be ordered hierarchically in a parts list structure

Function and error tree

SEs within the SE hierarchy are in following relationship with each other: the function of the inferior SEs (rubberlip) builds a chain to the superior (sealing ring), the function tree

one FMEA may contain several function trees

the function tree can be set up top down or bottom up

errors on a lower level can automatically be taken as a failure cause on a higher level complete support of system FMEA (see form)

Failure analysis

failure analysis can be considered in isolation for each malfunction failure analysis can be made within the function tree

a failure can cause several consecutive failures

a failure can result from several reasons

you can assign the RPZ factor meaning to a failure sequence 

you can assign the RPZ factor occurrence probability and detectability to a failure cause B, E and A from a catalogue, which can be created by the user (VDA, DGQ etc.)

Adjustment actions

The complete feature set of iQ-Projekte is used differentiation in preventive actions (design engineer) and detecting actions (later quality assurance) information about responsible person, appointments, performance, estimation of planned improvements etc. appointment traceability, follow-up actions in case of missed deadlines etc.

FMEA form

form for complete FMEA

form for certain system elements

Knowledgebase

structure and identification of FMEAs and SEs, which appear similar in other constructions or processes (for example bore for fit, rotation and parallel translation)

search algorithms based on class systems

adoption of already described SEs, depending on RPZ-experiences

Analysis

history of a FMEA about the version Pareto-diagram to a version over RPZ

graphic comparison of the RPZs over SEs and functions between two versions standard forms