The PRACE-2IP Work Package 5 (WP5), “Best Practices for HPC Systems Commissioning”, has two objectives: Procurement independent vendor relations and market watch (Task 1) Best practices for HPC Centre Infrastructures (Task 2) This Work Package builds on and expands the important work started in the PRACE Preparatory Phase project (PRACE-PP WP7) and continued through PRACE 1st Implementation Phase (PRACE-1IP WP8), which have all sought to reach informed decisions within PRACE as a whole on the acquisition and hosting of HPC systems and infrastructure. WP5 provides input for defining and updating procurement plans and strategies through the sharing of the state of the art and best practices in procuring and operating production HPC systems. The work package opens the possibility of closer co-operation between the PRACE community and infrastructure vendors, e.g. HPC, electricity, cooling, networking, but also security and infrastructure monitoring systems. Task 1 – Assessment of petascale systems – has performed a continuous market watch and analysis of trends in petascale HPC systems worldwide. The information, collected from public sources and industry conferences, is presented through comparisons and graphs that allow an easier and quicker examination of trends for different aspects of top-level HPC systems. Specific areas of interest are analysed in depth in terms of the market they belong to and the general HPC landscape, with a particular emphasis on the European point of view. As well as the general market analysis, this task also describes the link between hardware and software (in collaboration with software-specific work packages WP11 and WP12), providing information on the supported interfaces (programming models), benchmark results and user requirements. Task 2 – Best practices for designing and operating power efficient HPC centre infrastructures – has continued the production of white papers which explore specific topics related to HPC data centre design and operation, with input from PRACE members. It has also analysed the current state of the art in cooling and power efficient operating of HPC infrastructure. The deliverable D5.2 (Best Practices for HPC Procurement and Infrastructure) continues the work begun by report D5.1 published in February 2013. The additional information were compiled after the workshop organized in Lugano - 4th European HPC Centre Infrastructure Workshop (April 2013) and participation in the ISC 2013 conference and exhibition in Leipzig (June 2013). In addition, in July WP5 published a final version of the White Paper on Security in HPC Centres. This gives an overview of the current state of art of the most important security technologies used in data centres worldwide and it proposes a set of recommendations for PRACE HPC centres applicable to other HPC centres, as the white paper is publicly available. The deliverable updates the information about infrastructure issues for HPC data centres in Europe, U.S. and vendor solutions for building data centre infrastructures and smaller installations, so called mobile data centres. This illustrates important trends of the vendors’ new IT architectures, cooling and electricity. A special subsection is devoted to infrastructure management and monitoring systems. A new list of the Top500 fastest HPC systems and the Green500 list of the computing systems with the best energy to computing power efficiency were released in June 2013, and D5.2 makes a summary of petascale systems trends based on these lists and an analysis of the market. A new analysis of exascale systems and technologies required to support HPC with millions of CPUs and cores was also added: technologies for new data centres (required energy, cooling, green IT technology, the size and capacity computing rooms) and the IT technologies itself. For exascale systems, expected in 2018-2020, promising technologies and related basic research are presented. Finally the deliverable D5.2 presents PRACE and the European HPC Ecosystem in a Global Context.