TreeAge Software Guide Sensitivity Analysis Antie-Eater Open the - PDF document

TreeAge Software Guide – Sensitivity Analysis Antie-Eater Open the file Antie-Eater-0.trex OR build the following tree from scratch. To make the probability a variable, to be able to do sensitivity analysis on a variable: Double click on a probability  Rename it by typing “p”  Press “Enter”  A window appears as shown below  fill in the blank to specify a base case value of the probability, in this problem we entered “0.2”  Click OK

In TreeAge, # indicates: Change the 0.8 to # (in two places in the tree), 1 – sum of all other branches Change the 0.2 to p following the lower “Applesauce” branch In this case, 1 – p = # To run the sensitivity analysis: Click on the root node  Click on Analysis  Sensitivity Analysis  1 Way …

To specify that the variable p can range from 0 to 1: Set low value “0”, high value “1”, # of intervals to 10 (or to an appropriate number specific to your problem)  OK A graph should appear (n otice the “p” horizontal axis created 10 intervals as I indicated in the previous step):

Conducting 2-way Sensitivity Analysis Double click on the payoff and change it to the phrase “Highest_Value”  Click “OK” A window appears as shown below  fill in the blank with “15000”  Click “OK”  Click “OK”

Repeat the procedures from the previous page: Double Click on the “5000”  Change it to “Lowest_Value”  Enter “5000” in the blank  Click “OK”  Click “OK” Your tree should now look like the following, with three variables defined:

Click on the “root node”  Click Analysis  Sensitivity Analysis  2 Way… A window should appear, allowing you to select two variables to do two-way sensitivity analysis: Click on the “p” to see a drop down menu Click on “Lowest_Value”

Change the Low value and High value accordingly to your problem. Then Click OK Here we set the Variable Low value High Value Lowest_Value 5,000 9,000 Highest_Value 7,000 24,000 We leave the intervals at 4. That is the number of times TreeAge will perform the calculation. Notice in the figure below, there are four intervals along the horizontal and vertical axes.

To perform two- way sensitivity analysis between “p” and “Highest_Value” we perform similar pr ocedure as the two previous pages , except we choose the “p” this time. Select Analysis  Sensitivity Analysis  2 Way… Choose the “p” this time under Variable. Click OK A two-way sensitivity analysis graph should appear:

Conducting 3-way Sensitivity Analysis Click on the “root node”  Click on Analysis  Sensitivity Analysis  3- Way… Make sure each Low Value, High Value and Interval are applicable to your problem. Click OK The third variable (not on the graph’s axes): Move the slider on the right side of the screen to see different levels of the graph Sliding through you will see the following graphs… Lowest_Value = 6000 Lowest_Value = 7000 Lowest_Value = 9000

Tornado Diagram Click on the root node  Click on Analysis  Sensitivity Analysis  Tornado Diagram Make sure each Low Value, High Value and Interval are applicable to your problem. A Tornado graph should appear and be created in a new tab.