work center and shift sequences

Hi dears

I have maintained work break schedule, shift definition and shift sequences under one group no and assigned in work center ,I didn't maintain start time and finfish time in standard availed capacity in work center

and when i am creating production order system shown error as"

No working/operating time maintained in work center for scheduling

Message no. C7014"

Doubt 1: is it required tm maintained both standard available capacity time as well as shift sequence as grouping

Doubt2: how to assign work break schedule in shift definition or we can assign any where in directly in work center as i have two different break time in one shift

Abu Fathima