Lesson 8

Architectural analysis is the first of two steps in the design process. In this phase you match the requirements gathered from the project initiation and problem analysis phases and map them to the technologies and architectures that are best suited to support the requirements. You should now be able to:

1. Explain the purpose and function of architectural partitioning
2. Create architectural partitions and define their behaviors
3. Specify how responsibilities are distributed in two-tier, three-tier, and n-tier architectures
4. Apply the deployment diagram to model the system architecture

In the last module you learned how to partition the problem domain. In this module you learned how to break down each domain partition (or subsystem) into technological layers or tiers. The partitioning process followed a simple pattern of separate, assign responsibility, and reconnect using an interface. The result is a layered design with a set of highly cohesive partitions that are loosely coupled. This form of architecture improves the modularity of the system by isolating each unique type of design problem. Modularity, in turn, allows easier maintenance and updates to the system.

1. Architectural partitioning: Assigns technological layers to a domain partition
2. Cohesion: Cohesion is a measure of the degree to which all the parts of an object support a single purpose. High cohesion means that all the elements in the object support the same purpose. Low cohesion means that different elements support different purposes.
3. Coupling: A measure of the degree of dependency between model elements.
4. Three-tier architecture: A partitioning within a system that corresponds to the distribution of presentation, business logic, and data access.
5. N-tier architecture: The application of multiple technological layers of technology to support the distribution of the technological and functional responsibilities within an application, typically found in distributed systems.
6. Deployment diagram: The UML diagram used to model the hardware of the implementation environment.

Click the Exercise link below to work on the course project. In this exercise you will apply architectural partitioning to domain partitions.
Partition Project Domain - Exercise