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Overview

The tasks of the System Assembler are to retrieve components from existing repositories and connect them to build an assembly which is an essential part of the complete system. Connections are specified by using system assembly connectors to connect required roles of components with provided roles of other components. After connecting all components, the System Assembler puts the components into a system and defines the system provided and system required roles as well as the respective delegation connectors. The definition of a system and its boundaries is comparable to the definition of composite components. However, the difference is that composite components are built with the aim to use them in other composite components or assemblies. On contrary, systems are built to interact with other systems only. An overview of a system and its subconcepts is shown in figure 3.24.

Figure 3.24: A system and its assembly
Image system_overview

Components can only be used in contexts as introduced in section 2.5. Hence, the System Assembler is responsible to introduce system assembly contexts in which a component is put. When a component is put into a context its roles also become part of the context. Such roles which are part of a context can be connected. For this, a required role in a specific context is connected to a compatible provided role in an other context. A single component can be put into several different contexts and can be connected differently in each of them. As mentioned in section 2.5, the introduction of multiple assembly contexts is important as they capture the different influence of component external calls in different contexts.

The defined assembly model is finally passed on the the system deployer who specifies the allocation of the components to middle- and hardware environments. The assembly model is the second essential part of a system and is described in detail in section 3.4.


next up previous contents index
Next: Assembly Up: Component Assembler Previous: Component Assembler   Contents   Index
Snowball 2007-03-16