Soft-start is in theory the way to go, but it's very dependent on the motor type, there's a whole pile of different methods required for induction motors depending on whether they're capacitor-start, permanent split capacitor, shaded-pole, etc, so you can do it in some cases by lowering the voltage, or with a VFD, or a VSD, or the old-fashioned way with a centrifugal switch but that requires very careful handling. If as the OP said it's running million-dollar equipment you probably don't want to monkey with it at that level.