create trigger [dbo].[500]
on [dbo].[Table_4]

after INSERT
AS
BEGIN

insert into TABLE_5 (Date_Time,serial,ID,OPERATOR,program,color,part_customer)

select max (date_time), SERIAL, ID,OPERATOR,program,color, part_customer

 from TBL,table_4

where TBL.Scanned_id = table_4.PART_CUSTOMER

 group by SERIAL, ID,OPERATOR,program,color,part_customer
end

2015-08-28 12:21:05.880    104   1    A1      GT-20 Switch   2325
2015-08-28 12:21:14.293    105   1    A1      GT-17 Summit   2340
2015-08-28 12:21:14.293    105   1    A1      GT-17 Summit   2340
2015-08-28 12:21:50.820    105   9    B1      GT-17 Summit   2340