PLM Connection: ASML Handles Large Assemblies

By Dora Smith

Thanks to PLM Europe chair Maarten Romers for this report.

Johan Korten works at ASML supporting the NX users. Johan gave a presentation at PLM Europe on large assembly modeling at ASML. Here is an overview of his presentation, including a video interview.

ASML is headquartered in Veldhoven, the Netherlands and is the world’s leading provider of lithography systems for the semiconductor industry.

One of Johan’s projects was improving efficiency on using large assemblies. ASML is still working on NX 3. An NX upgrade is planned for next year.

ASML has large assemblies. Approximate 150,000 BOM lines and 25.000 unique parts. Loading complete assemblies is almost impossible.

In an earlier configuration management project Building Block (BB) were introduces. In general a machine BOM structure contains Production Modules (PM). PM’s contain BB’s and a BB can be anything between a mono or a 1000+ component assembly. BB’s are defined as the manageable parts since there are about 500 of these in each machine structure.

These BBs are also the typical levels most engineers work on in NX. By creating facet representations on a BB level, opening large assemblies will be much easier. The facets on BB level are favorite above the facets on monopart level. Tests showed loading facets on monopart level still would require to open the complete structure which might be 12 levels deep.

Having the facets on BB level do not require to open the complete structure. With the facets on BB level also the Reference Set ASSYFACET is introduced. So loading the assembly with a preferred reference loading order will help users to quickly open a part or assembly structure!

ASML created a small ufunc (user function) utility (external ufunc) to update modified BB facets in batch, every night. The utility runs under a special user account bbfacet. Basically all BBs with a last modifying user other then bbfacet need to be updated.

Since several machines are defined in NX, over 2000 BBs exist. Johan said only six of these had an issue updating in batch because of memory issues. But this can be updated manually. Users are happy with this new methodology. Combined with a new introduction on filters, efficiency goal was achieved. Loading assemblies is much faster!

Some issues still exist on large assemblies. However ASML is looking forward to upgrade to the latest version of NX where most of these issues will be solved as some people in the audience experienced.

The presentation is available via the PLM Europe web site.

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This article first appeared on the Siemens Digital Industries Software blog at