This document is a report delivered under Work Package 8 of the CloudLightning project, a Research and Innovation Action project supported by the European Union Horizon 2020 program.

The objectives of this document are:

• Determine the key determinants of cloud computing adoption decisions for HPC;
• Determine the present and future critical issues and problems facing HPC and the adoption of HPC in the Cloud from a stakeholder perspective.

Based upon the critical issues and problems identified through this research, industry, researchers and policymakers can more accurately design a roadmap and strategy to increase the adoption of HPC in the Cloud.