Cassandra is a role-based trust management language that utilizes Datalog with constraints to materialize security policies. A policy is a set of rules that can create and maintain roles, control users' access and manage different sets of information. With the help of Cassandra, the list of rules for NHS electronic health record system is constructed with readability. However, due to lack of real data and implementation, people cannot test and put their trust on the line. Patients often reject the ideas of sharing their information via a system if they cannot manage their own data. Doctors, on the other hand, will not use the system if it takes too long to respond, or has too many restrictions and ends up being hard to use. In this project, we focus on testing the system through analyzing its structure and the interaction between rules. We also try to revise the rules to improve readability while keeping the system's essence intact during the automated process.