Figure 1
shows the details of an indicator in the DSS.
Figure 1: Indicator details in the Indicator Manager
These details are:
- Indicator name: This is a unique name that is given to the indicator in order to use it within the DSS. It is recommended to have short names that are indicative and consistent across scenarios to facilitate comparison and MCA afterwards.
- Indicator description: This is a description of what the indicator does. This is optional and can be left empty. However, it is recommended to be used for documentation of indicators.
- Indicator script: This is the script that is used to calculate the indicator value
- Indicator parameters: These are the parameters that are needed by the script to calculate the indicator. They are described in detail in the following section.
- Indicator value: This is the value of the indicator that is calculated by the script
As explained above, the indicator parameters are one of the indicator details that need to be defined. Those parameters are added to the indicator definition when the script is added. An example is given in Figure 6.
Figure 6: Indicator parameters
In the above example, the selected indicator requires three parameters and each has a different value type. It is important to understand what each type does to determine which one should be used when creating a new indicator. Those parameters are all defined by the script assigned to calculate the designated indicator.
For time series data, the value type can be either 'Entity id' or 'Entity descriptor'. In both cases the value displayed next to the value type is the path to the time series, but in the database the specification is different.
For 'Entity id' the Indicator holds the ID of the object which is a constant even if the name or path of the time series is changed. This is useful if you are referring to a time series that its path and name can be changed (e.g. under a number of future scenarios). When you define an indicator within the Scenario Manager, the value type 'Entity id' is called 'Model reference'. They are used in the same way but have different names.
For “Entity descriptor” the database holds the path of the entity (i.e. static value). The path identifies the entity by name and location. This is useful when you are referring to a time series object that has same name and path (e.g. base case scenario).
The last value type is called 'Value' and it can represent number, string or Boolean variables. Numbers can be an integer, a float or a double.
The value type to use will depend upon the nature of the referred entity in order not to break the Indicator definition.