# Begin New Environment[LINK]

The calling point referred to with the keyword “BeginNewEnvironment” occurs once near the beginning of each environment period. Environment periods include sizing periods, design days, and run periods. This calling point will not be useful for control actions, but is useful for initializing variables and calculations that do not need to be repeated during each timestep. Once a value is set, Erl variables remember the value during the remainder of the environment period. However, they are automatically reinitialized to 0.0 at the beginning of each new environment period and this calling point executed again to redo the initializations. Considerable repetition can be avoided by designing Erl programs to use this calling point for initializations and calculations that are needed only once for each environment period. It is not called during individual timesteps. It is not called until well into the simulation after sizing and the final setup of actuators and internal variables.