Models management with a large number of models has placed demands on a highly structured and rigorous framework. The paper proposes a new framework, called RASES, that is based on the system entity structure (SES) formalism and the relational algebra (RA) formalism. These formalisms provide conceptual bases for the hierarchical management of models. Within the RASES framework, the hierarchical structures of models are represented in the form of entity structure that may be stored as relational tables in a database. Furthermore, several operations can be formulated in terms of relational algebra which can be coded in a standard query language such as the SQL. The RASES framework can be easily implemented on, and fully utilise the functionality of, the relational database management system (RDBMS). Huge amount of models and model structures, which is inevitable in the models management of real world systems, can be efficiently managed by virtue of the capability of RDBMS. The framework supports modellers to synthesise simulation models that meet their modelling objectives, and conduct appropriate experiments on the models under investigation.