Evolution of the Distributed Computing Model of the CMS experiment at the LHC

The Computing Model of the CMS experiment was prepared in 2005 and described in detail in the CMS Computing Technical Design Report. With the experience of the first years of LHC data taking and with the evolution of the available technologies, the CMS Collaboration identified areas where improvements were desirable. In this work we describe the most important modifications that have been, or are being implemented in the Distributed Computing Model of CMS. The Worldwide LHC computing Grid (WLCG) project acknowledged that the whole distributed computing infrastructure is impacted by this kind of changes that are happening in most LHC experiments and decided to create several Technical Evolution Groups (TEG) aiming at assessing the situation and at developing a strategy for the future. In this work we describe the CMS view on the TEG activities as well.