the duration of custom_tas is now fixed as requested by customer:
start custom_tas task from the creation date of confirm_solution till completion date of solution acceptance,

The issue is resolved now as customer has requested.

Dear Salem,

Kindly find attached the updated process to be uploaded.

@Natnael Asfaw
Kindly to apply the below scripts in order to fix the old data.

Script 1:

UPDATE SRD_TASK task
SET task.insertdate = (
SELECT cs.insertdate
FROM SRD_TASK cs
WHERE cs.REQUEST_ID = task.REQUEST_ID
AND cs.TASK_NAME = 'CONFIRM_SOLUTION'
)
WHERE task.TASK_NAME = 'CUSTOM_TAS_FIXED'
AND EXISTS (
SELECT 1
FROM SRD_TASK cs
WHERE cs.REQUEST_ID = task.REQUEST_ID
AND cs.TASK_NAME = 'CONFIRM_SOLUTION'
);

Script 2:

UPDATE SRD_REQUEST_EVENT e
SET e.start_time = (
SELECT inner_cs.start_time
FROM (
SELECT cs.start_time
FROM SRD_REQUEST_EVENT cs
WHERE cs.request_id = e.request_id
AND cs.task_name = 'CONFIRM_SOLUTION'
AND cs.start_time IS NOT NULL
) inner_cs
WHERE ROWNUM = 1
)
WHERE e.task_name = 'CUSTOM_TAS_FIXED'
AND EXISTS (
SELECT 1
FROM SRD_REQUEST_EVENT cs
WHERE cs.request_id = e.request_id
AND cs.task_name = 'CONFIRM_SOLUTION'
AND cs.start_time IS NOT NULL
);

Script 3:

UPDATE SRD_REQUEST_EVENT e
SET e.insertdate = (
SELECT inner_cs.insertdate
FROM (
SELECT cs.insertdate
FROM SRD_REQUEST_EVENT cs
WHERE cs.request_id = e.request_id
AND cs.task_name = 'CONFIRM_SOLUTION'
AND cs.insertdate IS NOT NULL
) inner_cs
WHERE ROWNUM = 1
)
WHERE e.task_name = 'CUSTOM_TAS_FIXED'
AND EXISTS (
SELECT 1
FROM SRD_REQUEST_EVENT cs
WHERE cs.request_id = e.request_id
AND cs.task_name = 'CONFIRM_SOLUTION'
AND cs.insertdate IS NOT NULL
);

Commit;

Email's attached.