Nicolas Teirlinckx Made for Software Engineering Groep 1 (2009 – 2010)

 Highest level design.  Structure of the system.  Reuse of patterns.  Comprise software components and relationship between them.  Strategic design.  Architectural layer. Build application layer by layer.  Qualities (extensible, flexible, reusable,…)

Sections about architecture in Software Design Document.

 Principal subsystems and their communications  Block-diagram with overview system structure.

 General model of control relationships between the subsystems.  UML, other tools (Rational Rose, Together).

 Give each category a score for the qualities.  And compare total scores.  Each quality has weight too.

 Use cases to check against requirements.  Can domain model be mapped to components?  All components necessary?  Defect detection.

Choosing an architecture for our auction website.

- Data processing. - Series of transformations on pieces of input data. - Final destination: output.

 Chain of processing elements.  No cycle of dataflow.  Output each element is input next.

 Finite number of steps linearly connected.  Components are independent programs.  One complement runs completely before other starts.

 There will be dataflow…  To limited to be used as architecture.  Can’t be used as highest level design.

- (n-tier architecture) - Client – server architecture. - Presentation, application processing and data management is separate. - Most widely used: three-tier.

- Partitions tasks between service providers and requesters. - Providers = servers, requesters = client. - Clients: web browser, clients, … - Providers: web servers, ftp servers, database servers, … - Independent components: strong reuse. - Interesting for auction site!

 A good alternative for our project.  Software architecture and design pattern.  Middle tier can be multi tiered.  Three tiers can be upgraded independently.

 Presentation tier: Website interface.  Logic tier: Give me all the items with layer “Lamp”.  Data tier: Item database.

- MVC architecture. - Often seen in web applications.

- Virtual machines (interpreters, …) - Repository architecture. - Event-driven architecture. - Real architecture are mix. - …

 Topologically different.  Three-tier: client never communicates with data.  MVC is triangular.  Three-tier: concept emerged 1990’s.  MVC: late 70’s.

Choose alternative between MVC and Three-tier for auction website!