Software Engineering course lecture 6

1. Lecture Six
Architectural design
Assistant Lecturer Huda A. Alameen
hudaa.alameen@uokufa.edu.iq

2. Introduction
 Architectural design is concerned with understanding how a system
should be organized and designing the overall structure of that
system.
 It is the critical link between design and requirements engineering,
as it identifies the main structural components in a system and the
relationships between them.

3. Communication Link
Subsystem
Subsystem
Subsystem
Subsystem Subsystem
Subsystem

4. Introduction
 Architecture in the small is concerned with the architecture of
individual programs. At this level, we are concerned with the way
that an individual program is decomposed into components.
 Architecture in the large is concerned with the architecture of
complex enterprise systems that include other systems, programs,
and program components.

5. Architectural design decisions
 Architectural design is a creative process where you design a system
organization that will satisfy the functional and non-functional
requirements of a system.
 Because of the close relationship between non-functional requirements
and software architecture.
 Performance Security Safety Availability Maintainability

6. Architectural views
View(s)
logical view (object classes)
A process view (run-time , interacting processes)
development view (software is decomposed)
physical view (system hardware)

7. MVC (Model-View-Controller)
Separates presentation and interaction from the system data.
The system is structured into three logical components that
interact with each other.
The Model component manages the system data and
associated operations on that data.
The View component defines and manages how the data is
presented to the user.
The Controller component manages user interaction (e.g.,
key presses, mouse clicks, etc.)

8. MVC

9. Code
complexity Allow data to change
independently

10. Architectural patterns
The idea of patterns as a way of presenting, sharing, and
reusing knowledge about software systems is now widely
used.
1)Layered architecture
2)Repository architecture
3)Client–server architecture

11. Layered architecture
 Organizes the system into layers with related functionality associated with each layer. A layer
provides services to the layer above it so the lowest-level layers represent core services that
are likely to be used throughout the system. (Allows replacement of entire layers )
clean
separation
between layers
Performance

12. Repository architecture
 All data in a system is managed in a central repository that is accessible to all
system components. Components do not interact directly, only through the
repository (Components can be independent ).
single point
Distributing the
repository

13. client–server
 In a client–server architecture, the functionality of the system is organized into
services, with each service delivered from a separate server. Clients are users of
these services and access servers to make use of them ( distributed across a
network(services) ).
Attack
Cause failure

14. Pipe and filter
The processing of the data in a system is organized so that
each processing component (filter) is discrete and carries
out one type of data transformation. The data flows (as in
a pipe) from one component to another for processing.