Manual for Life Cost Based FMEA
Forecast: Opportunity Frequency Chart
$279,884,395 $335,978,225 $392,072,054 Certainty is 49.88%f rom -Infinity to $332,986,554
Figure 5. Distribution of Opportunity Cost
13. Sensitivity analysis on each forecast can be made through sliding the triangle icon on underneath the distribution curve and reading the certainty level. More detail on how to interpret these graphs will be given in section 6.
5.2 Modeling MTBF using Weibull distribution
For components or subsystems where empirical data does not exist, MTBF can be modeled using Crystal Ball.
Move the cursor to the cell that requires a Weibull distribution analysis and type in the typical MTBF for that particular component
Select “Define Assumption” icon from the menu bar
From the popup window, select “Weibull Distribution” and click “OK” button.
Type in the location, scale, and shape factors from the table
Move the cursor to the cell that sums up the total cost
Select “Define Forecast” button on the main menu
Type in Forecast Name (e.g. “Labor Cost”)
Go to the menu bar and under “Run” select “Run Preferences”
Type “5000” under maximum number of trials and select “OK” button.
Select “Run” under the run menu bar.
Several popup windows should appear that correspond to the forecast name that was specified in step 8.
Modeling Parts Cost
Material cost which is a product of parts cost and quantity affected can be simulated using the steps in 5.1 and 5.2. Triangular distribution for cost of parts and quantity are used.
FMEA MANUAL By S. Rhee and C.M. Spencer