In this paper, we introduce a formal approach for composing software components into a distributed system. We describe the system as a hierarchical composition of some components, which can be distributed on a wide variety of hardware platforms and executed in parallel. We represent each component by a mathematical model and specify the abstract communication protocols of the components using Interface Automata (IAs). To model hierarchical systems, besides the basic components’ model, we will present other components, called nodes. A node consists of a set of subnodes interacting under the supervision of a controller. Each subnode, in turn, is a node or discrete event component. By considering a subnode as a node we can make hierarchical nodes/components. The entire system, therefore, forms the root of the hierarchy. A controller, in turn, is a set of subcontrollers/interface automata that specifies interaction protocol of the components inside a node. We have also presented an example demonstrating the model by illustrating nodes, subnodes, controllers, and subcontrollers. To address the state space explosion problem in system verification, we utilize the controller as a contract for independent analysis of the components and their interactions. Therefore, a node will not be analyzed directly; instead, we will analyze the controller.