\ncreate table #hardware(hardware_id int, dtime datetime, action_id int)

insert #hardware values(1, '20010101 00:00:00', 1)
insert #hardware values(2, '20010101 00:01:00', 1)
insert #hardware values(2, '20010101 00:10:00', 2)
insert #hardware values(1, '20010101 00:20:00', 2)
insert #hardware values(1, '20010101 00:30:00', 1)
insert #hardware values(1, '20010101 01:00:00', 2)
insert #hardware values(2, '20010101 01:00:00', 1)
insert #hardware values(1, '20010101 01:30:00', 1)
insert #hardware values(1, '20010101 01:35:00', 2)

/*время работы*/
select a.hardware_id, a.dtime as start, isnull((select top 1 dtime from #hardware b where b.hardware_id = a.hardware_id and b.action_id <> a.action_id and b.dtime > a.dtime order by b.dtime asc), getdate()) as stop
from #hardware a
where a.action_id = 1
order by a.hardware_id, a.dtime

/*время простоя*/
select a.hardware_id, a.dtime as start, isnull((select top 1 dtime from #hardware b where b.hardware_id = a.hardware_id and b.action_id <> a.action_id and b.dtime > a.dtime order by b.dtime asc), getdate()) as stop
from #hardware a
where a.action_id = 2
order by a.hardware_id, a.dtime

drop table #hardware