It is my understanding, from consultations with Jeppesen while trying to get an approach published somewhere else in the world, that they just re format an existing approach. They do no survey work them selves and rely on the originators calculations for safety (please correct this statement if not accurate) Therefore all requirements of DAPs in ENR 1.5 must be applied to assure the same level of safety. If these requirements can't be found in Jep pubs then this may be a problem? I believe a USAF 737 crash highlighted the risk of relying on Jep re formatted approaches with appropriate supporting documentation.