Capt Claret,
Perth SID/STAR/Route structure can no longer accomodate the increase in movements into, and out of, the Perth/Pearce/Jandakot Terminal Area. New SID/STAR have been proposed as an interim measure until a review of Western Australian airspace has been completed.
In 2003 an internal report of Breakdown of Separation in Australian airspace was published by Airservices Australia, called the BOS Review. Recommendation 14 of the review was to review Perth airspace and in particular, a collision risk associated with aircraft subject to a STAR clearance overshooting the turns at PEPPA and JENNA.
All recommendations of the BOS Review were required to have been implemented by the end of 2004.
It is now 2007 and the collision risk associated with Recommendation 14 still exists.