MEM APCH CTLR DESCRIBED INCOMPLETE POSITION RELIEF BRIEFING THAT CAUSED POTENTIAL LOSS OF SEPARATION EVENT.

Narrative

ON DIRECTION FROM THE SUPVR; I HAD JUST COMBINED BOTH E AND W ARR TO MY POS AS TFC WAS FAIRLY LIGHT. 1 CTLR WAS WORKING BOTH PARALLEL FINAL POS. I HAD ACR X; A HVY JET INBOUND FROM THE SW AND ACR Y A HVY JET; INBOUND FROM THE SE. I HAD A THIRD ACR HVY JET INBOUND FROM THE NE THAT WAS #1 IN THE 3 PLANE SEQUENCE. ALSO TAKING AWAY FROM MY ATTN WAS A VFR C182 REQUESTING A PRACTICE APCH WITH 2 ACFT OFF MY FREQ THAT REQUIRED NUMEROUS TFC CALLS. I HAD ASSIGNED ALL 3 ACFT RWY 36R FOR LNDG; REDUCED EACH TO 210 KTS; AND DSNDED EACH TO THE APPROPRIATE ALT FOR ENTRY INTO THE FINAL CTLR'S AIRSPACE. I DID NOT VERBALLY REQUEST APPROVAL FOR A RWY 36R ASSIGNMENT FOR ACR X FROM THE FINAL CTLR ALTHOUGH TFC WAS LIGHT AND THE ACFT TAGS WERE CLEARLY DENOTED. AS MY VFR TFC INCREASED THE SUPVR ASKED ANOTHER CTLR TO SPLIT THE W ARR POS FROM ME. I GAVE THE CTLR A FULL BRIEFING; INCLUDING ADVISING THAT CTLR OF THE ONLY TFC ON THE W SIDE OF THE AIRSPACE WHICH WAS ACFT X; TAGGED FOR THE R; ON A 070 DEG HDG; REDUCED TO 210 KTS; DSNDING GO 6000 FT. THE FINAL CTLR ACCEPTED HDOFS OF ALL 3 ACR ACFT WITHOUT QUESTION. SHORTLY THEREAFTER; THE FINAL CTLR CLRED ACFT X FOR AN APCH TO RWY 36L; AND ACFT X JOINED THE LOC FOR RWY 36R; COMING IN POSSIBLE CONFLICT WITH ACFT Y OR THE OTHER ACR ACFT. AS I WRITE THIS; THE INVESTIGATION IS STILL UNDER WAY TO DETERMINE IF THERE WAS A LOSS OF SEPARATION. I DO NOT NORMALLY WORK WITH THE CTLR THAT WAS WORKING THE FINAL POS; AND I SHOULD HAVE VERBALLY REQUESTED APPROVAL TO ASSIGN ACFT X; RWY 36R; BUT I ALSO BELIEVE THAT THE FINAL CTLR SHOULD HAVE BEEN MORE AWARE OF THE 3 ACFT TAGS THAT HE HAD ACCEPTED HDOFS ON. I ALSO BELIEVE THAT THE SUPVR'S DECISION TO COMBINE AND THEN DECOMBINE THE ARR POS IN THE SPAN OF ABOUT 15 MINS PLAYED A ROLE IN DISTRACTING ME FROM THE VERBAL NOTIFICATION. EACH CONFIGN OF THE ARR POS REQUIRED MULTIPLE KEYBOARD ENTRIES TO SET THE RADAR SCOPE CONFIGNS AND FULL BRIEFINGS OF THE TFC. THESE DUTIES TOOK TIME THAT I MAY HAVE USED TO VERBALLY REQUEST THE RWY ASSIGNMENT FOR ACFT X WITH THE FINAL CTLR.