How to flatten (or ‘explode’) a Syspro Bill Of Material (BOM): recursive loop vs. simple temp table method
Presenting Syspro’s BOMs in a ‘flattened’ (or ‘exploded’) format in Excel or in SQL Server is very handy for doing/checking Costings or doing Advanced Trail Kits.
My initial attempt at flattening BOMs was to use the TSQL recursive loop method:
WITH FlatBom(ParentPart, Component, BomLevel, RequiredQty)
AS (
— Anchor
SELECT StockCode AS ‘ParentPart’,
StockCode AS ‘Component’,
1,
CAST(0 AS DECIMAL (12,6))
FROM dbo.InvMaster
WHERE StockCode = ‘YourParentStockCode’ — Insert your Parent item – or list of Parent items – in here
UNION ALL
— Recursive call
SELECT BOM.ParentPart AS ‘ParentPart’,
BOM.Component AS ‘Component’,
BomLevel + 1,
QtyPer
FROM FlatBom CTE
JOIN(SELECT
ParentPart AS ‘ParentPart’,
Component AS ‘Component’,
QtyPer
FROM dbo.BomStructure
WHERE Route = ‘1’ AND ParentPart IS NOT NULL AND ParentPart <> ‘ ‘ –Note Route
) AS BOM
ON CTE.Component = BOM.ParentPart
)
SELECT * FROM FlatBom
But I found this method to be extremely slow – especially when one has thousands of multilevel BOMs. A whole lot of articles on the Net confirms this – and discourages the use of recursive loops.
As simple (and much faster) alternative is to use a (temp) table with an insert for each of your BOM levels:
SELECT ParentPart AS [Parent], 1 AS [BomLevel], ParentPart, Component, QtyPer AS [RequiredQty]
INTO #FlatBom
FROM dbo.BomStructure
WHERE ParentPart = ‘YourParentStockCode’ — Insert your Parent item – or list of Parent items – in here
AND Route = ‘1’;
INSERT INTO #FlatBom(Parent, BomLevel, ParentPart, Component, RequiredQty)
SELECT t.Parent, 2, b.ParentPart, b.Component, b.QtyPer
FROM dbo.BomStructure b
INNER JOIN #FlatBom t ON t.Component = b.ParentPart
WHERE Route = ‘1’;
INSERT INTO #FlatBom(Parent, BomLevel, ParentPart, Component, RequiredQty)
SELECT t.Parent, 3, b.ParentPart, b.Component, b.QtyPer
FROM dbo.BomStructure b
INNER JOIN #FlatBom t ON t.Component = b.ParentPart AND t.BomLevel = 2
WHERE Route = ‘1’
AND t.BomLevel = 2;
INSERT INTO #FlatBom(Parent, BomLevel, ParentPart, Component, RequiredQty)
SELECT t.Parent, 4, b.ParentPart, b.Component, b.QtyPer
FROM dbo.BomStructure b
INNER JOIN #FlatBom t ON t.Component = b.ParentPart AND t.BomLevel = 3
WHERE Route = ‘1’
AND t.BomLevel = 3;
… — Repeat, for your MAX BomLevel times
SELECT * FROM #FlatBom
I would suggest including the ScrapPercentage and other attributes in your flattening script to make (e.g.) Costings and Trail Kits more accurate.
