AS employment headlines go from grim to grimmer, it’s appropriate that one job category with expanding demand involves helping people avoid reality. Designers of computer simulations are sought in many fields to help understand complex, multifaceted phenomena that are too expensive or perilous to study in real life.

Simulations are used to gauge the impact that new rivals in the market may have on a company’s sales  or to help a manufacturer devise the cheapest, fastest means of delivering products.

To reduce costs measured in lives, not dollars, simulations examine responses in security threat situations, for instance, or how various factors affect aircraft or rocket-engine performance.

“The fundamental nature of modeling and simulation is to represent something that’s in the world out there in a way that you can manipulate and think about without risk and at low cost,” said Bill Waite, chairman of the AEgis Technologies Group, a Huntsville, Ala., company that creates simulations for various military and civilian applications.