Welcome... it would help if you provided DDL and sample data and what you expect to see as a result. There's a link to a posting guide somewhere, one of these days I'll add it to my cool sig.

Based on what you've said here's a sample "sample" and "DDL" of what you can provide to help us help you.

declare @BenchTest as table(ID int Identity(1,1), PartNumber int

, PartName varchar(10), TestDate datetime default getdate());

insert into @BenchTest(PartNumber, PartName)

values(1,'A'),(2,'B'),(3,'C'),(4,'D'),(1,'A'),(2,'B'),(3,'C')

,(4,'D'),(1,'A'),(2,'B'),(3,'C'),(4,'D'),(1,'A'),(2,'B')

select ID

, PartNumber

, PartName

, ROW_NUMBER()Over(Partition by PartNumber Order by (Select Null)) CycleNum

, count(*)Over(Partition by PartNumber) TotalCycle

, TestDate

from @BenchTest

order by PartNumber