SAMM

The SAMM (Scenario and Model Management) component of the whatIf? suite supports the use of systems simulation models for scenario analysis. It facilitates the creation and display of of scenarios - where a scenario consists of the set of values for the input variables and the corresponding values of the output variables that are generated from these inputs. As simulation models may be used to generate large numbers of scenarios, it is essential to keep track of the combinations of input values that give rise to each scenario. In simulation models consisting of hundreds or thousands of variables, it is clear that scenario management is a significant problem. SAMM is unique in its scenario management capabilities in that it is designed to take advantage of the fact that values for input variables may be shared among multiple scenarios and that the values of the ouptput variables can be recreated if the pointers to the set of input values associated with each scenario is maintained.

While most modelling environments allow only a single scenario to be created and used at any one time, SAMM has facilities for scenario comparison so that those input variables whose values differ from scenario to scenario can be easily identified and displayed. Scenarios are colour coded to facilitate comparative graphical displays.

SAMM Features

  • Scenario management for maintaining the integrity of multiple scenarios - SAMM allows new assumptions to be quickly created and compared and avoids duplication of data.

  • Scenarios (sets of assumptions) can be documented and colour coded for visual comparison.

  • A hierarchy structure is used to organize and manage the components of a framework.

  • SAMM automatically manages the linkages and flows of information among sub-model components.

  • SAMM uses "lazy evaluation" - computation of model components only as required.

  • SAMM supports model families and the use of calibration models to link historical data to simulation models.

  • SAMM supports custom reports or views for displaying model ouput and for filling input variables.

  • SAMM provides facilities for documenting new instances of variables and scenarios.