Some Basic Considerations on the Design and the Interpretation of Indicators. . .
13
Fig. 5 The general structure of a model component with integrated valuating model by hierarchical indicator
This is the necessary and sufficient indicator structure for an indicator based on
a simple model. However, to transfer the situation to models based on a modularhierarchical model specification, the situation grows more complex. With respect to
Sect. 4 that introduced a hierarchically structured indicator-tree the specification for
the aggregating indicator has to be defined more precisely.
Structural, the situation is as follows: The hierarchical model consists of model
components with three defining parts (without loss of generality, we follow the
model description language of (Zeigler 1990)):
– declarations,
– dynamic description,
– specification of the connections.
The indicator part of a model component consists of:
– indicator quantities (A–C in the list above)
– aggregation description (D in the list above)
– specification of the connections (see Fig. 2)
In result, the model component has to be extended according to Fig. 5.
Some special remarks are necessary concerning the interpretation of the
connections-part of this extended model component specification: As in model
hierarchy, the component has to specify to which other indicator-calculation the
value of the aggregated indicator function AIV has to be connected.
Structural, this connection is completely analogues to the connections of model
quantities in the model hierarchy. Therefore, the connection part for the indicator is
common with the connection part of the standard-modelling part of the component.
Doing so, the indicator-hierarchy according to Fig. 2 can be built by already existing
concepts for building and maintaining model-hierarchies.
Beside this structural identity, it has to be emphasized that the indicator hierarchy
might completely differ from the model hierarchy.
Following precisely the steps for model design (Wittmann 2016) in building
indicators, it becomes obvious that the indicator model has to be submitted to an
indicator validation (according to model validation), and an intensive sensitivity
analysis.
13
Fig. 5 The general structure of a model component with integrated valuating model by hierarchical indicator
This is the necessary and sufficient indicator structure for an indicator based on
a simple model. However, to transfer the situation to models based on a modularhierarchical model specification, the situation grows more complex. With respect to
Sect. 4 that introduced a hierarchically structured indicator-tree the specification for
the aggregating indicator has to be defined more precisely.
Structural, the situation is as follows: The hierarchical model consists of model
components with three defining parts (without loss of generality, we follow the
model description language of (Zeigler 1990)):
– declarations,
– dynamic description,
– specification of the connections.
The indicator part of a model component consists of:
– indicator quantities (A–C in the list above)
– aggregation description (D in the list above)
– specification of the connections (see Fig. 2)
In result, the model component has to be extended according to Fig. 5.
Some special remarks are necessary concerning the interpretation of the
connections-part of this extended model component specification: As in model
hierarchy, the component has to specify to which other indicator-calculation the
value of the aggregated indicator function AIV has to be connected.
Structural, this connection is completely analogues to the connections of model
quantities in the model hierarchy. Therefore, the connection part for the indicator is
common with the connection part of the standard-modelling part of the component.
Doing so, the indicator-hierarchy according to Fig. 2 can be built by already existing
concepts for building and maintaining model-hierarchies.
Beside this structural identity, it has to be emphasized that the indicator hierarchy
might completely differ from the model hierarchy.
Following precisely the steps for model design (Wittmann 2016) in building
indicators, it becomes obvious that the indicator model has to be submitted to an
indicator validation (according to model validation), and an intensive sensitivity
analysis.