Declare @OrigTab Table(Part varchar(30), qty int)

insert into @OrigTab

select 'X51','3' union

select 'A5','1' union

select '123','2' union

select '054','5'

select * from @OrigTab ORDER BY 1 DESC

;WITH

-- Make an inline tally table (CTE)

E1(N) AS (

SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL

SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL

SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1

), --10E+1 or 10 rows

E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows

Tally(N) AS (SELECT 1 FROM E2 a, E2 b)

-- use the tally table as a source of rows

SELECT

TAG = 'PNM-'+RIGHT('0'+CAST(ROW_NUMBER() OVER(ORDER BY Part DESC) AS VARCHAR(2)),2),

o.Part,

o.qty

FROM @OrigTab o

CROSS APPLY (SELECT TOP(o.qty) N FROM Tally) x

ORDER BY Part DESC