Impact Diagrams

You can obtain a complete view of all relations that are associated with a particular series by generating an impact diagram. Click the label for KPI_19 in the Overall Model System chart, right-click, and select Create Impact Diagram.

Figure 1. Impact Diagram of effects
Impact Diagram of effects

When an impact diagram is created from the Overall Model System, as in this example, it initially shows the series that are affected by the selected series. By default, impact diagrams show three levels of effects, where the first level is just the series of interest. Each additional level shows more indirect effects of the series of interest. You can change the value of the Number of levels to display to show more or fewer levels of effects. The impact diagram for this example shows that KPI_19 is a direct input to both KPI_18 and KPI_7, but it indirectly affects a number of series through its effect on series KPI_7. As in the overall model system, the thickness of the lines indicates the significance of the causal relations.

The chart that is displayed in each node of the impact diagram shows the last L+1 values of the associated series at the end of the estimation period and any forecast values, where L is the number of lag terms that are included in each model. You can obtain a detailed sequence chart of these values by single-clicking the associated node.

Double-clicking a node sets the associated series as the series of interest, and regenerates the impact diagram based on that series. You can also specify a series name in the Series of interest box to select a different series of interest.

Impact diagrams can also show the series that affect the series of interest. These series are referred to as causes. To see the series that affect KPI_19, select Causes of series from the Show drop-down.

Figure 2. Impact Diagram of causes
Impact Diagram of causes

This view shows that the model for KPI_19 has four inputs and that Lever3 has the most significant causal connection with KPI_19. It also shows series that indirectly affect KPI_19 through their effects on KPI_7 and KPI_17. The same concept of levels that was discussed for effects also applies to causes. Likewise, you can change the value of the Number of levels to display to show more or fewer levels of causes.

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