Distributed Computing Beyond The Grid

This note will summarize the Software development and operational experience and improvements of the ATLAS Distributed Computing in the past years. Grid model was successfully deployed for all HEP experiments and after the first two years of very successful LHC data-taking and processing on the Grid we need to assess our experience and to find a good balance between stability and innovation. Several Research and Development (RnD) pilot projects were launched by ATLAS (and HEP) computing communities, namely 'cloud computing', data storage federation. HEP experiments are also adopted data popularity model and it allows to migrate from planned data placement to the dynamic model. This talk will also present an overview of HEP experiments computing model evolution and increasing role of networking as one of major resources (in addition to storage and CPU) which should be taken into account by workload management and data management systems.