How to add Average along with sum - sql

Question

My query is :
select
TIERING_2, ASP_NAME ,
sum(case when SUBCASE_MEASURED = '1' AND FE_TYPE = 'ASP' AND CLOSE_MONTH = '3' and region = 'EEMEA' AND SCHEDULED_RESCHEDULED = 'Scheduled' then 1 else 0 end) DA_SCHEDULED,
sum(case when SUBCASE_MEASURED = '1' AND FE_TYPE = 'ASP' AND CLOSE_MONTH = '3' and region = 'EEMEA' AND SCHEDULED_RESCHEDULED = 'Reactive' then 1 else 0 end) FE_DELAY,
sum(case when SUBCASE_MEASURED = '1' AND FE_TYPE = 'ASP' AND CLOSE_MONTH = '3' and region = 'EEMEA' AND SCHEDULED_RESCHEDULED = 'Reactive' then 1 else 0 end)Onsite_Time,
sum(case when SUBCASE_MEASURED = '1' AND FE_TYPE = 'ASP' AND region = 'EEMEA' AND SCHEDULED_RESCHEDULED = 'Reactive' and LATE_START_CONF_INDICATOR = '0'then 1 else 0 end) Late_hours,
sum(case when SUBCASE_MEASURED = '1' AND FE_TYPE = 'ASP' AND CLOSE_MONTH = '3' AND ASP_ON_TIME = '1' then 1 else 0 end) ON_TIME
from table_Control_kpi GROUP BY ASP_NAME , TIERING_2
However along with sum i want average onsite time.
Can someone help me to club the below query with the above query
SELECT AVG(ONSITE_TIME)
FROM table_Control_kpi
WHERE SCHEDULED_RESCHEDULED = 'Reactive'
AND ASP_NAME='3D Networks'
AND SUBCASE_MEASURED = '1'
AND FE_TYPE = 'ASP'
AND CLOSE_MONTH = '3'

Answer 1

Maybe use a window function?
SELECT TIERING_2, ASP_NAME ,
--all the sums up there
,AVG(CASE
WHEN SCHEDULED_RESCHEDULED = 'Reactive'
AND ASP_NAME='3D Networks'
AND SUBCASE_MEASURED = '1'
AND FE_TYPE = 'ASP'
AND CLOSE_MONTH = '3'
THEN ONSITE_TIME END) OVER ()
FROM table_Control_kpi GROUP BY ASP_NAME , TIERING_2