The SMI must honor several design constraints. Although the primary focus is on the automated pilot which controls a single aircraft, there may be additional agents associated with a vehicle. A fighter aircraft may have a Radio Intercept Officer (RIO) and an Air Intercept Control (AIC) aircraft may have air controllers. Any of these agents may be created or destroyed at any time; there is no preset scenario.
An arbitrary number of agents may exist in the Soar system and an arbitrary number of vehicles may exist in ModSAF. Not all of these vehicles may be controlled by Soar agents. Some agents may be controlled by other software modules or even humans. The number of such entities is limited only by the processing speed and memory capacity of the host workstation. The SMI must be efficient so that Soar and ModSAF do not degrade due to excessive communication overhead between pilots and their vehicles.
There are also implementation constraints on the SMI. Both Soar and ModSAF are designed as standalone systems and continue to see ongoing development. The SMI must enable new versions of Soar and ModSAF to be incorporated.