Abstract. Cloud computing is an emergent technology that has generated significant interest in the marketplace and is forecasted for high growth. Moreover, Cloud computing has a great impact on different type of users from individual consumers and businesses to small and medium size (SMBs) and enterprise businesses. Although there are many benefits to adopting Cloud computing, there are significant barriers to adoption, viz. security and privacy. In this paper, we focus on carefully planning security aspects regarding access control of Cloud computing solutions before implementing them and, furthermore, on ensuring they satisfy particular organizational security requirements. Specifically, we propose a methodology for the development of access control systems. The methodology is capable of utilizing existing security requirements engineering approaches for the definition and evaluation of access control models, and verification of access control systems against organizational security requirements using techniques that are based on formal methods. A proof of concept example is provided that demonstrates the application of the proposed methodology on Cloud computing systems.