Page 60 - Root Cause Failure Analysis

Root Cause Failure Analysis Methodology 51

Before acting on a recommendation for corrective action that seriously affects deliv-
ery, the decision to implement and its timing should be closely coordinated with the
Sales and Customer Service Departments. These groups are in a better position to
evaluate the potential impact of product delays than the investigator or investigating
team.

Implementation Costs
Implementing change, no matter what the change is, will have a one-time cost. Most
important, implementing many potential corrective actions will force a system shut-
down. In many cases, this single factor will determine which-if any--of the poten-
tial corrective actions can be implemented.

Therefore, the loss of production capacity and the revenue it generates is a cost that
must be considered in the cost-benefit analysis. The analysis must include all the costs,
direct and indirect, required to implement the recommended change. For example,
replacing a damaged or defective pump will incur costs that include lost capacity
because of downtime, pump procurement, labor to install the new pump, and other mis-
cellaneous costs. Other corrective actions, such as improving the skill level of plant per-
sonnel, also have implementation costs. In this case, costs include the salary of the
employees to be trained, training course development costs, instructor cost, and so forth.

Many of these costs are obvious (i.e., material and labor required to install a
machine), but others are hidden and easily overlooked. For example, replacing a
machine or system component normally will require some period of downtime to
make the change. The losses in capacity and labor costs for the idle product crew not
always are apparent and can mistakenly be omitted from the analysis.

Materials Many of the potential actions discovered through RCFA involve repair-
ing, replacing, or modifying existing machinery or systems. Each action must be eval-
uated to determine the real material costs of the proposed changes.

Exercise great care to identify all significant material costs. For example, replacing a
centrifugal pump may require a new foundation, complete repiping of both the suc-
tion and discharge system, additional spare parts, and a myriad of other material-
related costs. It is crucial that the evaluation accurately identify all direct and indirect
costs due to the potential corrective action.

Labor Estimating labor costs typically is more difficult than determining material
costs. Without accurate records of the level of effort required to repair, replace. or
modify a machine or process, it is extremely difficult to estimate the actual labor
involved in a potential corrective action. Simple tasks, such as replacing a bearing,
often can be quantified-and the time involved may appear to be relatively insignifi-
cant. However, many machines require complete or partial disassembly before the
bearing can be replaced.