Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 3007; Flight Crew Type 2310
Situational Awareness; Workload
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Human Factors; Procedure
Descending via CREDE3; we were set up and planning on RNAV RNP Z 16R with the CLFFF translation selected. Through 14-13;000 ft; Approach advised unable RNAV; expect Visual 16R. I prompted the Captain if he wanted me to reprogram the FMC to the ILS16R or leave it as is. Approaching LONGS and descending Captain reprogrammed FMC to ILS16R approach and executed before it could be [verified]. This caused the CREDE3 arrival to be dropped and the aircraft entered CWS (Control Wheel Steering). I reprogrammed CREDE3 and using HDG initiated a left turn to 355 degrees. However; by this point we had overshot LONGS. ATC assigned HDG 310 and 11;000 feet. We [continued] to a visual approach and landing. Going into Denver; approach and runway changes are expected. The biggest lesson here is the importance of [FMC route verification]; heads down on CDU in a high workload environment; and connecting a transition fix into the FMC; without clearance.
B737NG First Officer reported a track deviation occurred on arrival into DEN following a late clearance change and improper FMC loading.