When you have entered all required data and have created Alternatives, you are ready to perform a Simulation. A Simulation is where you specify the time window and time interval parameters for either a single Alternative or a group of Alternatives. After a successful Simulation, you can analyze the results, make revisions, and perform additional Simulations to better evaluate the reservoir operations in your watershed.

When you create a simulation, you must specify a simulation time window and select the alternatives to be analyzed. ResSim then creates a folder with the name of the simulation in the rss folder of the watershed; this folder represents the simulation. Within this simulation folder will be a partial copy of the watershed, including only those files needed by the selected alternatives. Also created in the simulation folder is a DSS file named simulation.dss, which will contain all the DSS records that represent the input and output for the selected alternatives.