Spreadsheet Linking Overview
DPL provides a complete set of features for linking to Excel spreadsheets. Most DPL analyses involve spreadsheet linking at some point. This summarizes DPL's main spreadsheet linking features and gives suggestions on when and why to use each feature.
Before using a spreadsheet with DPL, you need to give names to the driver and output metric cells you will be linking to. See Excel's documentation for information on how to name cells.
Calculation links are appropriate when the value measures being used for the analysis are calculated in a spreadsheet model, usually a financial model producing NPV, IRR, etc. Most DPL analyses employ calculation links, and there are several ways to set them up. With calculation links driver cells in the spreadsheet are linked to DPL Driver nodes (usually chance and decision nodes), and spreadsheet metrics (e.g., NPV) are linked to DPL Metric nodes (a value node with no node data). When you run an analysis, DPL sends the values from the DPL Driver nodes to the spreadsheet, tells Excel to recalculate, and then gathers Excel's values for the DPL Metric nodes. This process takes place for every scenario (path) in the tree.
There are a few ways to set up calculation links:
- If you have a spreadsheet but are starting from a blank DPL model, use Home | Workspace | Add | Excel Linked Model.
- If you want to add new nodes to a model, use Influence Diagram | Node | Linked Node | Excel Calculation-Linked.
- If you want to link an existing node to a cell in the spreadsheet, use Links tab of the Node Definition dialog.
- If you want to link all events in the decision tree, use Link Events.
Initialization links allow you to use spreadsheet data to initialize nodes. For example, you might want a chance node to take its probabilities from a table in Excel. If you want to add new initialization linked nodes to a model, use Influence Diagram | Node | Linked Node | Excel Initialization-Linked.
Spreadsheet conversion allows you to speed up an analysis by translating your spreadsheet into DPL code.
Managing Spreadsheet Links
Once your spreadsheet links have been established, most maintenance activities can be done from the Manage Links dialog. You can get to the Manage Links dialog by choosing Influence Diagram/Decision Tree | Links | Manage. Within the dialog you can change the location of a linked spreadsheet, remove links, update a converted spreadsheet and view a list of linked nodes.
Versions: DPL Professional, DPL Enterprise, DPL Portfolio