# IFC tool performance: normalization and round-trip preservation as enabler for BIM-Level 3-CDEs **URL:** \ **Category:** Developers\ **Created:** [November 26, 2019, 2:52am UTC](https://forums.buildingsmart.org/t/ifc-tool-performance-normalization-and-round-trip-preservation-as-enabler-for-bim-level-3-cdes/2052 "2019-11-26T02:52:38Z")\ **Posts on this page:** 1\ **Showing post:** 5
**Author:** ![ReD\_CoDE](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.buildingsmart.org/red_code/32/226_2.png) [@ReD\_CoDE](https://forums.buildingsmart.org/u/ReD_CoDE)\ **Post date:** [December 11, 2019, 12:11am UTC](https://forums.buildingsmart.org/t/ifc-tool-performance-normalization-and-round-trip-preservation-as-enabler-for-bim-level-3-cdes/2052/5 "2019-12-11T00:11:07Z")
I warned you about this: > [@COBie and IFC mapping](https://forums.buildingsmart.org/t/cobie-and-ifc-mapping/1796/11): > > Both IFC and COBie spreadsheet are not “static” and most of the times, COBie spreadsheet doesn’t use just as an archive (which the input data just comes from IFC file) For this reason “you have to have a mechanism to archive changes inside the spreadsheet” IFC has IfcOwnerHistory yes, but as you mentioned nobody uses it and even bSI is thinking to drop it. But I think it’s useful, especially after ISO 19650 which mainly focuses on legal aspects, so owner and owner history becomes important Al… And I think you follow a mechanism, as “diff” that is used to some “old?” databases for version control, but I think it’d be good and efficient (I don’t have any idea, because I’m not a programmer) --- _[View the full topic](https://forums.buildingsmart.org/t/ifc-tool-performance-normalization-and-round-trip-preservation-as-enabler-for-bim-level-3-cdes/2052)._