ATLAS experience with the modeling of SM processes in the context of Higgs studies / BSM searches

much is known from the ATLAS/CMS SM articles about the performance of qcd tools (e.g. from the studies of W/Z+jets cross sections, top quark distributions, etc). A bit less is known about the efforts that are needed to ensure a proper description of backgrounds in the BSM searches or in Higgs studies. In the searches, for example, control samples are used, to avoid the need of inaccurate MC models, or to reweight improper modeling. Sometimes we don't see in teh final papers what is happening behind the scenes, and it's hard to learn about possible modeling issues. Are there clear deficiencies that, if fixed, would make your work simpler and more effective? These talks should focus on these specific aspects of the H and BSM studies. In other words, they should neither report H or BSM results, nor report on generic SM measurements, but give some perspective on the current status and on the possible needs for future improvements of SM modeling for H precision studies and BSM searches.