The Ingenieur Vol 59 July-Sept 2014 The Ingenieur Vo. 59, July-Sept 2014 | Page 15

Figure 2.0: A typical effective FMEA process diagram.

followed by identifying all of the associated
elements in the product that could cause that top
event to occur. Fault trees provide a convenient
symbolic representation of the combination of
events resulting in the occurrence of the top
event. Events and gates in fault tree analysis are
represented by symbols. The entire product, as
well as human interactions, are analyzed when
performing a fault tree analysis. While building the
fault tree and performing the analysis, a review
of information regarding codes, standards, and
research documents associated with processes,
procedures, and equipment for the product, along
with the human interface and factual evidence
relevant to the actual and potential accident event,
is required. [4], [5], [7].
Figure 1.0 is an example of basic fault tree
logic.
Fault-tree diagram is useful. It allows the
process system engineer and his team to plan
and undertake the hazard and risk analysis
systematically, and provides a logical path to follow
during the analysis on the product.

Failure Modes and Effects
Analysis
Failure Modes and Effects Analysis (FMEA) is a
simple but useful tool or method for considering
potential and actual failure modes in a product in
a systematic and rational way. Potential problems
can be tackled at an early stage in product design
and development which is safe engineering
practice rather than in a panic after the occurrence
of a failure. The method stands a much greater
chance of success in solving problems if the
engineers know how to recognize defects, and how
to correct them once identified. The findings of a
FMEA evaluation are then recorded in tabular form
or on a FMEA work sheet.
This technique is widely used in many
industries and is required by many standards and
codes of engineering practice. Next, a ranking
evaluation of the various ways to reduce potential
and actual risk of the product is assessed.

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