B737 reported descending below a crossing restriction during arrival.

Attributes
ACN	1753339
Time
Date	202007
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 148 Flight Crew Type 2895
Person 2
Function	Pilot Flying Captain
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Last 90 Days 135 Flight Crew Type 135
Events
Anomaly	Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter Weather / Turbulence

Narrative:

We were vectored off the STAR to follow another aircraft that was deviating around weather. We were then given direct zzzzz; not on the STAR; to cross at 12;000 ft. Then direct ZZZZZ1; on the STAR; and descend via the arrival. I noticed the aircraft leveling off at 12;000 ft. We were then given direct to ZZZZZ1 to cross at 12;000 ft. And descend via the arrival. During the confirmation procedure; I noticed 12;000 ft. On the pfd and 12;000 ft. On the FMS for ZZZZZ1; but I associated the bottom altitude of 11;000 ft. With descend via instruction instead of the current instruction of crossing the fix at 12;000 ft.; then descend via.therefore; I confirmed the FMS for execution. I proceeded to review my STAR approach plate to confirm the bottom altitude on the arrival. ATC amended the instruction and cleared us to 11;000 ft. I was under the impression that we were complying with ATC instruction until the captain queried if we missed a crossing restriction.

Original NASA ASRS Text

Title: B737 reported descending below a crossing restriction during arrival.

Narrative: We were vectored off the STAR to follow another aircraft that was deviating around weather. We were then given direct ZZZZZ; not on the STAR; to cross at 12;000 ft. then direct ZZZZZ1; on the STAR; and DESCEND VIA the arrival. I noticed the aircraft leveling off at 12;000 ft. We were then given direct to ZZZZZ1 to cross at 12;000 ft. and descend via the Arrival. During the confirmation procedure; I noticed 12;000 ft. on the PFD and 12;000 ft. on the FMS for ZZZZZ1; but I associated the bottom altitude of 11;000 ft. with descend via instruction instead of the current instruction of crossing the fix at 12;000 ft.; then descend via.Therefore; I confirmed the FMS for execution. I proceeded to review my STAR Approach Plate to confirm the bottom altitude on the arrival. ATC amended the instruction and cleared us to 11;000 ft. I was under the impression that we were complying with ATC instruction until the Captain queried if we missed a crossing restriction.

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.