This paper discusses cloud ERP security challenges and their existing solutions. Initially, a set of definitions associated with ERP systems, cloud computing, and multi-tenancy, along with their respective challenges and issues regarding security and privacy, are provided. Next, a set of security challenges is listed, discussed, and mapped to the existing solutions to solve these problems. This thesis aims to build an effective approach to the cloud ERP security management model in terms of data storage, data virtualization, data isolation, and access security in cloud ERP. The following proposed techniques are used to improve the security for multi-tenant SaaS: database virtualization, implementation of data encryption and search functionality on databases and developed systems, distribution of data between tenant and ERP providers, secure application deployment in multi-tenant environments, implementation of the authentication and developed systems together as a two-factor authentication, and improved user access control for multi-tenant ERP clouds