Date: 201504
Local time of day: 1201-1800
Location: LAX.Airport, CA
Flight conditions: VMC
Light: Daylight
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class E SCT
ATC / advisory: TRACON SCT
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Situational Awareness
Second reporter function: Pilot Flying; First Officer
Anomaly: ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: Established and well ahead of the aircraft on the SEAVU 2 Arrival to LAX with clearance to descend to 17000 feet; we were directed to fly fast disregarding the arrival speeds. The FMC legs page had been fully checked and briefed while confidently planning; checking; and briefing a visual approach to Runway 24R since ATIS stated Runway 25L was closed. Descending through approximately FL220; new ATIS was available just prior to handoff from Center. As pilot monitoring; all at once; I had to get ATIS cross-cockpit (since the First Officer had the only MCDU); facilitate a descent check; monitor the level off at 17;000 feet; performed a frequency change to Approach Control; while acknowledging a clearance to descend via and cleared the ILS 25L Approach; re-compute landing data (because of the new ATIS) to a runway that was now open; assigned; and not expected; while struggling with a performance computer that had a sabotaged on/off switch; then reprogram the FMC for the new runway; then crosschecked the legs page once again. While confirming new approach frequency; course; and touchdown zone altitude bugs; which all compounded to not quite enough situational awareness left over to realize that the pilot flying had not updated the MCP altitude window to correspond with our descend via/approach clearance. Obviously; the aircraft did not initiate an automatic descent out of 17;000 feet; so we totally missed the published crossing restriction at SEAVU. Approach Control's radio call inquiring our ability to make the restriction was when we became aware of our mistake. We were then assigned a hard altitude; assigned progressively slower airspeeds to 250 knots and 210 knots compounding our descent dilemma; and given a vector off the approach. We configured early with landing gear quickly getting back on profile. We acknowledged the field in sight when queried; and then flew a visual approach to an uneventful landing. Yes; we made one significant altitude error; but we were led down the primrose path with a late descend via clearance on the arrival with faster than published speeds; assigned an approach clearance to a runway that was previously unavailable; and task saturated with numerous arrival task 'do-overs' at a critical point on the arrival.I was task saturated because too many changes occurred at a time compressed point on the arrival. LAX is notorious for clearances that challenge us. Is there any way to get an earlier notification of runway assignment?


Second narrative: [Report Narrative Contained No Additional Information.]


Synopsis: B737 flight crew reported missing a crossing restriction on the SEAVU2 Arrival into LAX when they received a late runway change.