“…Loosely coupled [31,32,55,56,63,66,84,85,90,93,94] (Design) Patterns [26,35,47,69,81] Modelling languages [29,40,46,54,64,85,87,97] Cloud federation [39,78,81,82,98] Security by design [44,47,52,68,71,73,80,95,99] Technologies [17, 31, 50-52, 56, 60, 63, 69, 89, 92, 95, 96, 100] Standards [8,17,26,40,45,48 complex challenge to be solved, due to the heterogeneity of the cloud management systems employed by the providers. Thus, multi-provider infrastructure operation under a federation of independent clouds and/or infrastructure components is still a challenge.…”