Using the TreePlan Add-In for Excel

1 This video shows how to use the TreePlan add-in for working with decision trees in Excel. I will be working inside Windows Excel, but these instructions should apply -- more or less -- to Macintosh Excel also. 2 First, make sure that you have the TreePlan add-in somewhere locally accessible. In my case, I have the add-in stored in a folder on the desktop. Be sure that the add-in is *not* contained within a zip archive. 3 To start Excel with the add-in enabled, double click the TreePlan add-in. After loading, Excel will probably ask if you'd like to allow macros. This is so that TreePlan can work properly. Confirm by clicking the button labeled Enable Macros. 4 Then open a worksheet. Here, I'll just start with a brand new worksheet ... I'm going to turn off the gridlines also. This is just my own personal preference so that the decision tree will be a little easier to see. 5 If TreePlan has loaded correctly, you should have a new ribbon -- the Add-Ins ribbon -- on the right here. Click it to see the menu buttons for TreePlan. In fact, all three buttons here do the exact same thing when clicked. They each call up the TreePlan software. So you can click any of them while working with the software. 6 Probably the most important thing to remember when working with TreePlan is that --- whenever you'd like to create a tree, copy and paste in the tree, or modify the structure of the tree in any way --- you *must* go through the TreePlan software. Otherwise, your tree can get corrupted and unusable. 7 So, to get started, call up the software by clicking one of the three buttons. You should be prompted for a New Tree, which you can go ahead and click. You'll then be presented with a basic tree, the structure and contents of which you can alter. 8 You can start by changing some of the decision labels and some of the cash flows. For these changes, you can type directly in the spreadsheet cells, but be careful not to overwrite the formula cells -- for example, the one that you see here. These formula cells are controlled by TreePlan, and if you accidentally change them, your tree won't work properly. 9 Next, you can add to the tree by selecting one of the triangle terminal nodes and calling up TreePlan. Let's change the terminal node to an event node with three branches. When you click OK, TreePlan will update your tree ... You can then alter the branch names and, because it is an event node, you can also alter the branch probabilities. Just always make sure that your probabilities add up to a total of 100%. Otherwise, TreePlan's formulas won't calculate properly. 10 When selecting elements of the tree to change, it is usually best to select cells with your keyboard keys -- not with the mouse. For example, if I use my mouse to select a terminal node here, I accidentally select the graphics object (the little triangle), not the cell itself. So I usually use my keyboard keys to make sure I have truly selected the cell. 11 At this point, you can simply play around with TreePlan to get the tree structure that you want. You have to be a little careful because there is no Undo function, but if you save your file pretty often, it's safe just to try TreePlan's various features. 12 For example, you can copy and paste parts of your tree using the TreePlan menu. Let's use the cursor to select this event node and then call up TreePlan and select Copy Subtree. And click OK. Then go to a new location, select the cell, call up TreePlan, and choose Paste Subtree. You can see that the tree expands with the new copied portion. 13 One final word of note. When you're done working with TreePlan and close down Excel, if you reopen Excel in a standard way, say, from the Windows menu here, then the TreePlan add-in will not be enabled. So whenever you need to work with TreePlan, be sure to open it from the add-in itself as described at the beginning of this video.