1. A method for performing a real-time, in-the-field switching-sequence simulation for a power system that includes a plurality of switching devices, comprising: receiving, at a smart key, a first simulation result indicating that an operation on a switching device is allowed, wherein the first simulation is performed at a first site, and wherein the switching device is located at a second site; receiving a request, from a user at the smart key which is carried to a vicinity of the switching device at the second site, to perform the operation on the switching device; in response to the request, identifying the switching device from the plurality of switching devices; obtaining instant status information associated with the plurality of switching devices; and running a second simulation, at the smart key located in the vicinity of the switching device, based on the instant status information and the identified switching device; and in response to determining that the operation is allowed based on an outcome of the second simulation, unlocking, by the smart key, a lock associated with the switching device, thus facilitating performance of the operation.