All Silico core simulation elements (Variables, Stocks and Flows) have two time series - simulated and actual. When entering a formula for an element, this defines how the simulated series will be calculated. This will have the full power of all Silico functions in order to generate a result.
It is often useful to have other data for each element, the 'actual' data, which can be used in several ways, as examples:
To compare the predicted (simulated) time series against real-world data.
To use outside data as the simulated value, for data external to the model.
To track against a desired outcome, such as a performance target.
Using Actual Values
The Actual series can be used for simulated data in two distinct ways:
The actual values will be used implicitly if the formula for an element is left blank. If there are no actual values, then the result will be
The actual value can be used explicitly with the special local variable
@actual. This also allows the actual data to be adjusted by the simulated formula, e.g. quickly checking impact of 10% higher/lower values.
The default mode of operation for actuals is as an inline table within the element inspector. This can be editing in the table itself, or by drawing onto the chart within the inspector.
This allows to quickly 'sketch' in assumptions when prototyping, or quickly customise the data. When linking an element into a Table element, the actuals will also be editable in that view.
The other mode for actuals is to derive them from other data, using a formula (as you would for simulated data). This allows to reference external data from datatables as well as to derive actuals from other elements.
Referencing Other Elements
Frequently, the data to be compared against is actually a derivation from other already existing data. For example, if you have two departmental targets, the total target could be the sum of those individual departments. While you could calculate and input the sum separately, this is error-prone and additional work. Instead, you can add a computed actual for the element.
Using the tab above the formula, you can switch to Actual and then toggle the actual to be defined using a formula. Entering a formula then allows to derive the actuals from the connected elements. When referencing elements in this way, the value will be their Actual value, not their simulated value.
Using a DataTable
Another use for computed actuals is to reference externally defined data. This is frequently done using the DataTable element. Normally, DataTable values are treated as simulated values. However, in the same way as above, you can use them to bring in external data to compare against at the element level.