ETOPS is a requirement for two-engine airplanes. It is also only applicable to part 91 operations and part121 carriers (commercial). If you work for a 121 carrier, they have already gotten approval from the FAA to operate ETOPS on their OPSPEC. All of the large aircraft manufacturers put out a list of requirements for each aircraft model (i.e. B767, A330, etc) that covers every service bulletin and regulatory requirement that the aircraft must meet in order for it to be eligible for ETOPS operation. The regulatory agencies rely on those lists, they do not make them up themselves. I have included a link to the FAA Advisory Circular that covers this subject.