**7.8 Concluding remarks**

As we already stressed, the WLCG performance during the LHC data taking in 2009-2011 was excellent and the basic mission of the WLCG has been fulfilled: the data taking and processing is ongoing without major show-stoppers, hundreds of people are using the Grid to perform their analysis and unique scientific results are delivered within weeks after the data was recorded. In addition, the experience gained during this data taking .stress test. launched new strategies to be followed on the way of the future WLCG development. There are fundamental issues like the approaching lack of WLCG resources and the expansion of new technologies like the Cloud computing. In the time of writing this chapter it looks like we will see in the future some combination of Grid and Cloud technologies will be adopted to operate the distributed computing infrastructures used by the HEP experiments.
