Narrative:

There were multiple aircraft situations that preceded this loss of separation. A light aircraft at 14000 feet west bound. Multiple burbank arrivals and a bfl departure; destination lax at 13000 feet. The arrival at 14000 feet was in the middle of the sector adding complexity. I meant to stop another landing aircraft above 15000 feet; but apparently issued 14000 feet instead. When that aircraft didn't stop descent I vectored it to the west to avoid the other aircraft at 14000 feet who I also turned to avoid that situation. Meanwhile; aircraft X was under both aircraft at 13000 feet and not sequenced with aircraft Y and another aircraft. Both were from high altitude descending via a STAR. I vectored the bfl departure to the east to follow aircraft Y; then turned it back; too soon; and lost separation with aircraft Y. In post incident review the best solution would have been to hand the bfl to lax aircraft off to adjacent sector for routing via their lax stream and eliminate that aircraft from the scenario. It also would have helped if I had called the sector to the east for control to descend the sba arrival aircraft. I find that the descend via procedures that we implemented have added complexity to the sectors. There are numerous new fixes along the routes and more of them. One factor that slowed me down was in the above situation was having to look up a fix for the arrival to rejoin the STAR after I vectored it off route. The user request evaluation tool (uret) didn't display it when I looked. Additionally; the aircraft are now descending into the sectors from high altitude versus before when they only entered after a clearance.

Related reports:

Google
 

Original NASA ASRS Text

Title: A Center controller reported the vector for sequencing was insufficient and resulted in less than required separation.

Narrative: There were multiple aircraft situations that preceded this loss of separation. A light aircraft at 14000 feet west bound. Multiple Burbank arrivals and a BFL departure; destination LAX at 13000 feet. The arrival at 14000 feet was in the middle of the sector adding complexity. I meant to stop another landing aircraft above 15000 feet; but apparently issued 14000 feet instead. When that aircraft didn't stop descent I vectored it to the west to avoid the other aircraft at 14000 feet who I also turned to avoid that situation. Meanwhile; Aircraft X was under both aircraft at 13000 feet and not sequenced with Aircraft Y and another aircraft. Both were from high altitude descending via a STAR. I vectored the BFL departure to the east to follow Aircraft Y; then turned it back; too soon; and lost separation with Aircraft Y. In post incident review the best solution would have been to hand the BFL to LAX aircraft off to adjacent sector for routing via their LAX stream and eliminate that aircraft from the scenario. It also would have helped if I had called the sector to the east for control to descend the SBA arrival aircraft. I find that the descend via procedures that we implemented have added complexity to the sectors. There are numerous new fixes along the routes and more of them. One factor that slowed me down was in the above situation was having to look up a fix for the arrival to rejoin the STAR after I vectored it off route. The User Request Evaluation Tool (URET) didn't display it when I looked. Additionally; the aircraft are now descending into the sectors from high altitude versus before when they only entered after a clearance.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.