Ventana software support forum

Greetings,

I dont know how youve designed your model, but I would suggest backcasting.
This is where you "set" the model back to a "time" in the past, before the
intended period that the models run is to cover. Then, you run it "forward"
and evaluate its output results against reality.

I prefer building systems models that are based on profit and loss and
balance sheets of organizations, and demographic and sales data, and then
"mating" that information to submodels reflecting the real-world phenomena
that produced the fiscal numbers.

This attempt is more useful to the people running the organizations you are
attempting to represent, in the first place. It also forces less abstraction
and a harder focus on institutional dynamics.

Im using this practice with a new sim called The Oakland As Microworld.
Its designed around real information on the team, and permits the user to
"run" the baseball organization over a ten-year period. Its not -- yet --
based around players, and when that submodel is installed, one will be asked
to "pitch" a contract the the "player" and a salary structure will result
from that "interaction."

For the present, one can set single game and season ticket prices, total
player payroll, scouting and player development expenses, team marketing
expenses, and build a new stadium. If one chooses to construct a new
stadium, there are nine different revenue streams that can be used in various
combinations. If too much public tax money is proposed for use, the stadium
may not be approved for construction.

In this sim, one cant just charge any ticket price: the higher the price,
the fewer people who will purchase them, depending on team won and loss
record and the economys conditions.

In this, information to model from varies, but the direction of change is the
same. And thats the point. Pay attention to the direction of change in one
variable with respect to change in the variable its dependent on. The
change should be within historical real world perameters.

The objective is to make a sim that feels like the real world youre modeling.

Zennie Abraham
Subject: REPLY Validation of SD-models? (SD3907)