B737 Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 120; Flight Crew Total 18000; Flight Crew Type 4466
Workload; Training / Qualification; Time Pressure; Situational Awareness
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Environment - Non Weather Related; Human Factors
Prior to top of descent we briefed the NNCEE 1 RNAV Arrival into IAH.  The arrival says to plan on flying the RWY 8R transition.  So we briefed the ILS RWY 8R approach.  Houston Approach Control then told us to fly the RNAV (RNP) Y RWY 9 approach.  The CA was the PM and told the FO he would change the approach in the FMC.  After selecting the new approach the CA told the FO that there was a discontinuity at HOWLN.  By selecting the HOWLN transition two separate HOWLN fixes were created separated by a discontinuity.  The discontinuity appeared at the top of page two in the legs page of the FMC.  So the CA brought up the second HOWLN fix and entered it into the discontinuity boxes and assumed that this action closed the discontinuity.  But he never went back to page one to verify that the discontinuity was closed and he did not ask the FO to verify it as the FO was busy managing the descent.  The MCP displayed LNAV and VNAV were engaged and so did the FMAs.  Approach Control then said at HOWLN you are cleared the RNAV (RNP) Y RWY 9 approach.  So the CA set FAF altitude of 2;000 in the MCP.  The FO went through LAVSFT and at HOWLN (IAF) had me set TDZE of 100.  Then we both said why isn't the airplane turning?  Tower immediately cancelled our approach clearance and vectored us for the ILS RWY 9 approach.  The CA was on a larger scale than the FO and noticed that the magenta line showed both the RF leg turn inbound but also extended beyond HOWLN as well and said I think I did not clean up the discontinuity correctly.  The contributing factors were both pilots did not verify the legs page after the Captain cleaned up the discontinuity and the high workload environment in IMC.  Additionally it was the FO's first trip in over a month.
I briefed the ILS 8R per listed as the runway for flying the NNCEE1 Arrival.  During our descent when checking in with Houston approach we were given a new runaway RNAV Y runway 9.  The captain put the new runway into the FMS and Verbalized he was cleaning it for the RF.  I was reviewing the approach plate and didn't verify his FMS inputs.  The CA noticed right away that the plane should be starting to turn for the RF; which ATC cancelled our approach and told to fly a heading.
Air carrier flight crew reported a track deviation on the mid-approach segment due to a high workload environment coupled with the First Officer's extended period of time off.