B717 FLT CREW DESCENDED THROUGH AN ALT RESTRICTION WHILE PROGRAMMING THE FMS.

Narrative

FLT PLAN LOADED AT GATE ALONG WITH DEST RWY (ILS 1) AND NEW ALT CONSTRAINTS PER FDC NOTAMS AND COMPANY MESSAGES. WHILE ENRTE; RECEIVED DIRECT ESL ON ELDEE 3 ARR. LATER ISSUED CROSS 35 MI W ESL AT FL290. ENTERED INTO FMS. ATIS ADVISED LDA -- DME 19. CHANGED RWY IN FMS; BUT IN DOING SO; CLRED SOME XING RESTRS ON ELDEE 3; AND REVERTED SOME RESTRS TO OLD RESTRS. ALSO; WAYPOINTS THAT MAKE UP 19 ARR (HOOOK; CAPTL; ETC) WERE NOT LOADED. ALSO SLOWED IN ANTICIPATION OF HOLDING FOR HVY RAIN AND TSTM ON FIELD. CLRED TO DSND VIA ELDEE 3; FO INSERTED AND VERIFIED. FMS WAS BEHIND CALCULATING XING AT DRUZZ (15000 FT); AND SIMULTANEOUSLY FO ANNOUNCED HE WAS 'REFRESHING' THE XING RESTR AT DRUZZ. CAPT SCROLLED VERT SPD TO MAKE DRUZZ AT 15000 FT; AND COMMANDED 8000 FT IN THE ALT WINDOW; THE LOWEST ALT ON THE ARR. CREW BECAME DISTR BY NEW FIXES AND RESETTING ALT RESTRS; AND ACFT DSNDED BELOW 15000 FT AFTER DRUZZ. FO NOTICED AND CALLED OUT. CAPT DISCONNECTED AUTOPLT AND BEGAN CLB. FO CALLED ATC TO ADVISE. ATC STATED; 'MAINTAIN 13000 FT; DSND VIA ELDEE 3; YOU'RE FINE.' FLT COMPLETED WITHOUT INCIDENT. NO TFC CONFLICTS.