In this article, you will find a tutorial on how to create YoY Bridges, as well as an explanation of their calculation logic.

A Year-over-Year Bridge shows the change between two periods using the effects of Assumptions. In contrast, a Scenario Bridge can be used to analyse the change between two different Scenarios in a specific period.

Creating a YoY Bridge

Use the Tile Chart Wizard to create a new YoY Bridge. After selecting the Node you want to analyze the Bridge will be created. 

Configuration options:

  • Node: The Bridge always displays values for a selected Node in the Model. You can change the Node after the Bridge is created by selecting a different Node in the Inspector.

  • Scenario Selection: By default, a single Scenario will be selected for the Bridge. In case you have Scenarios building on top of each other, e.g. a Base-Case and Simulation Scenarios, you can select additional Scenarios using the Scenarios filter for the Bridge. Remember to bring the Scenarios into the right order using Sort and Format. The first Scenario will be used as the foundation for the effect calculation of the second Scenario, therefore potential differences between the selected time period in the underlying Scenario will be shown as the first entries in the YOY Bridge.
  • Time Level: You can use the Inspector to transition between any time period (e.g. months, quarters or years). By default, the Bridge will be created for years. To change to a different period select Configure Axes and swap "Year" for the desired time level (e.g. "Quarter" or "Month").

  • Period Selection: Depending on the chosen time level for the Bridge, a Filter for the respective level, e.g. Years (Data Series) is available. You can use this Filter to select the two periods the YoY Bridge should show. Selecting e.g. 2017 and 2020 will result in a Bridge with the summed up effects of the three years.  In case only a single period is selected the Bridge will automatically use the previous period as a reference point for the YoY bridge. 
  • Assumption Properties: If you have configured Assumption Properties, you can also view a YoY Bridge by these Properties instead of the single Assumptions. Just select the respective Property in the dropdown for the x-axis of the Bridge.

You can switch between Scenario and YoY Bridges by using the option Bridge between periods in the Inspector.

Calculation Logic

To illustrate the calculation logic behind the effects for individual Assumptions, let's consider the simple example of the Node Revenue. Adjustments can be made using Assumptions with a base effect, which means that the adjustment is carried into the following years. Alternativly, Assumptions can be one-time adjustments without an effect on the following years. 

Assumptions without base effect / one time:

Assumption 1 (no base effect)+10+15+20
Assumption 2 (no base effect)-+20-

Assumptions with base effect:

Revenue PY-2035
Assumption 3 (with base effect)+10--
Assumption 4 (with base effect)+10+15+20

The calculation logic determines the individual effects for all Assumptions that are active in the selected Scenario between the two viewed periods.
A YoY Bridge for 17/18 or 18/19 would display the following effects:

YoY Effect 17/18YoY Effect 18/19
Assumption 1 (no base effect)+5+5
Assumption 2 (no base effect)+20-20
Assumption 3 (with base effect)00
Assumption 4 (with base effect)+15+20