You should check the discussions in this bug log:

bugs.launchpad.net/openobject-addons/+bug/985525

I know the functionality has slighly improved in OpenERP v7.0.

One work-around in 6.1 I found that worked (well sort-of) -....

a) first create a BOM without any components, but ensure all workcentres and other information has been added

b) Then create the BOM components with reference to the same products (but with different quantities) and also referencing Parent BOM (in the properties/parent BOM field)

c) When complete you can open the parent BOM again and see the multiple sub-components have been added

As I needed an exact sequence of material on the BOM this seems the only way I could create the master BOM.

Nevertheless, the main issue with this work-around is you can't change anything on the master BOM again - without getting the error message :

"ValidateError - Error occurred while validating the field(s) product_id: BoM line product should not be same as BoM product"

The error message in this case is also misleading as the final product (Master BOM) is not included anywhere in the BOM component list - so there is no issues with recursive errors of the same product on this BOM. I only have many repeating items in a BOM - but with varying quantities.

As you can imagine this is really irritating when you have over 10.000's products !

well, this problem is persisted in many kind of industries and the solutions proposed here work nice for a particular case but do not change the fact that many industries need the freedom to get the BOM right and not like currently openERP ask us to do. therefore I am trying to fix it on my site but with little success.

in my case I have a SMT assembly with a high number of components in such BOM's. I made a short example:

• R001 - R1206100MFF - 1pc
• R002 - R120610K0FF - 1pc
• R003 - R1206100MFF - 1pc

we do not even write the BOM by hands but extract it out of the DB and upload it to ERP to write this BOM different ( I mean writing the R001 and R003 in one line) would create problems:

1. it would make the maintenance of the BOM difficult
2. it would make creation of an placement list impossible therefore lead to keeping 2 BOM's in the same time( one for ERP and one in query friendly form (and now we have a recipe for disaster...)

the "material pick-up list" should

• take the BOM and ignore the designations,
• group the ArticleNo
• and sum the QTY's. this would be the clean way of working and takes no effort on the SQL site.

the validation should be as an option but not as a must.

it would be great if someone found a fix for this but I am afraid this issue is so hard coded that it is difficult to work around.

Have you tried creating a Phantom BOM for each position of the 'real' BOM?

1 of XY + 10 of A2 would be one phantom BOM

1 of ZZ + 23 of A2 would be the second phantom BOM.

The warehouseman would look at the STOCK MOVES for his instructions to get the total number of screws for a given order or day, the worker would look at the MANUFACTURING ORDER to know which step to use those screws.