Page 28 - Root Cause Failure Analysis

Root Cause Failure Analysis Methodology 19

In most cases, the failed machine must be replaced immediately to minimize its
impact on production. If this is the case, evaluating the system surrounding the inci-
dent may be beneficial.

Operating Performance
Deviations in operating performance may occur without the physical failure of critical
production equipment or systems. Chronic deviations may justify the use of RCFA as
a means of resolving the recurring problem.

Generally, chronic product quality and capacity problems require a full RCFA. How-
ever, care must be exercised to ensure that these problems are recumng and have a
significant impact on plant performance before using this problem-solving technique.

Product Quality
Deviations in first-time-through product quality are prime candidates for RCFA,
which can be used to resolve most quality-related problems. However, the analysis
should not be used for all quality problems. Nonrecumng deviations or those that
have no significant impact on capacity or costs are not cost-effective applications.

Capacity Restrictions
Many of the problems or events that occur affect a plant’s ability to consistently meet
expected production or capacity rates. These problems may be suitable for RCFA, but
further evaluation is recommended before beginning an analysis. After the initial
investigation, if the event can be fully qualified and a cost-effective solution not
found, then a full analysis should be considered. Note that an analysis normally is not
performed on random, nonrecumng events or equipment failures.

Economic Performance
Deviations in economic performance, such as high production or maintenance costs,
often warrant the use of RCFA. The decision tree and specific steps required to
resolve these problems vary depending on the type of problem and its forcing func-
tions or causes.

Safety
Any event that has a potential for causing personal injury should be investigated
immediately. While events in this classification may not warrant a full RCFA, they
must be resolved as quickly as possible.

Isolating the root cause of injury-causing accidents or events generally is more diffi-
cult than for equipment failures and requires a different problem-solving approach.
The primary reason for this increased difficulty is that the cause often is subjective.