In general, indicators are used in
either describing the state of a system or in monitoring and evaluation. To
describe the state of a system, a number of indicators are defined then
measured, calculated or estimated at a certain interval to show the state of
different system aspects. In this case indicators are called 'State
Indicators'. For monitoring and evaluation, the indicators focus more on the
performance or impact of a measure/strategy (e.g. a project) rather than the
state of a system. The indicator values are collected at certain intervals
(usually much shorter than the state indicators) and then evaluated to check
the system progress, spot weaknesses and problems and suggest solutions.
In the DSS, the indicators are used to compare the scenario performance either against a base scenario (e.g. present conditions) or against other scenarios to find the optimum solution to a problem or number of problems. They can also be used in Multi Criteria Analysis (MCA) and Cost Benefit Analysis (CBA). In this case, one or more indicators are used to define a criterion that represents a certain aspect of a scenario (e.g. minimum flow to satisfy environmental conditions). Those criteria are then analyzed and compared to find the most favorable scenario. More details on the use of indicators to compare scenarios to undertake MCA and/or CBA are in the Scenario Manager and Analysis Manager training modules respectively.
It should be also noted that indicators can be time series to show, for example, the trend of one aspect of a system but the DSS does not support generating such type of indicators. Monitoring the state of the system entails such time series for “State Indicators” that are periodically estimated or measured.
Connection between indicators and scripts in the DSS
In the DSS, a script needs to be assigned to an indicator. This script implements the algorithm that is used to calculate the indicator. No matter how simple or complex the indicator is, a script needs to be created within the Script Manager to calculate the value of an indicator. For more information on creating scripts see the Scripts Manager training module.
Connection between the Scenario and Indicator Managers
In order to calculate the indicator values for a scenario, Indicators need to be first created for this scenario. Following that, this scenario is run creating a simulation where scenario outputs are stored. These outputs are then used to calculate the indicator values as a post-processing step. Those steps (i.e. creation of indicators, running a scenario and calculation of indicator values) are done within the Scenario Manager. If the simulation is run the indicators defined within the scenarios are added in the indicator manager to simply view the list of indicators under each scenario.
Testing whether a scenario indicator can be calculated or not can also be done in the Indicator manager. But, the indicator needs to be created first within the Scenario Manager because the Indicator Manager can only support static inputs for scripts. To provide dynamic inputs, the indicators are to be defined from the scenario manager (For more information on this topic see the Scenario Manager training module).
Connection between the Analysis and Indicator Managers
In a Multi Criteria Analysis (MCA) that is done in the Analysis Manager, the Indicator Manager can be used to define indicators which are not based on simulation results (i.e. costs). This is done by defining the indicator within the Indicator Manager and then it can be imported into an MCA within the Analysis Manager (For more information on this topic see the Analysis Manager training module).