The document discusses software architecture design. It defines software architecture as the structure of components, relationships between components, and properties of components. An architectural design model can be applied to other systems and represents predictable ways to describe architecture. The architecture represents a system and enables analysis of effectiveness in meeting requirements and reducing risks. Key aspects of architectural design include communication between stakeholders, controlling complexity, consistency, reducing risks, and enabling reuse. Common architectural styles discussed include data-centered, data flow, call-and-return, object-oriented, and layered architectures.

1. Software
Architecture Design
• Presented By
• Faraz Imllak Mayo
• Fall 18 BSIT 055 (B)
• Software Engineering

2. Definitions
• The software architecture of a program or computing system is
the structure or structures of the system which comprise
– The software components
– The externally visible properties of those components
– The relationships among the components
• Software architectural design represents the structure of the
data and program components that are required to build a
computer-based system
• An architectural design model is transferable
– It can be applied to the design of other systems
– It represents a set of abstractions that enable software engineers to
describe architecture in predictable ways

3. Why Architecture?
The architecture is not the operational software. Rather, it is a
representation that enables a software engineer to:
(1)analyze the effectiveness of the design in meeting its stated
requirements,
(2)reduce the risks associated with the construction of the
software.

4. Why is Architecture
Important?
• Representations of software architecture are an enabler for
communication between all parties (stakeholders) interested
in the development of a computer-based system.
 Controls complexity
 Gives Consistency
 Reduces risk
 Enables re-use

5. Architectural Design Process
• Basic Steps
– Creation of the data design
– Derivation of one or more representations of the architectural
structure of the system
– Analysis of alternative architectural styles to choose the one best
suited to customer requirements and quality attributes
– Elaboration of the architecture based on the selected architectural
style
• A database designer creates the data architecture for a system
to represent the data components
• A system architect selects an appropriate architectural style
derived during system engineering and software requirements
analysis

6. Architecture attributes
Performance
Localise operations to minimise sub-system
communication
Security
Use a layered architecture with critical assets in inner
layers
Safety
Isolate safety-critical components
Availability
Include redundant components in the architecture
Maintainability
Use fine-grain, self-contained components

7. Architecture design
decisions
Architecture design is a creative process, so the process is
depend on the type of system being developed.
A number of common decisions to design all process;
 Is there a general application architecture that can be
used?
 How will the system be distributed?
 Which style of construction is appropriate?
 What approach will be used to design the system?
 How will the system merge into modules?
 Which control strategy should be used?
 How will architectural design be reviewed?
 How should architecture be documented?
•

8. Architecture models
 Static model
 Dynamic model
 Interface model
 Relationship model
 Distribution model

9. Software Architectural
Styles

10. Architectural Styles
Each style describes a system category that encompasses:
(1)a set of components (a system, e.g., a database, computational modules)
that perform a function required by
(2)a set of connectors that enable “communication, coordination and
cooperation” among components,
(3)constraints that define how components can be integrated to form the
system,
 Data-centered architectures
 Data flow architectures
 Call and return architectures
 Object-oriented architectures
 Layered architectures

11. Data-Centered
Architecture

12. Data Flow Style
• Characterized by viewing the system as a series of
transformations on successive pieces of input data
• Data enters the system and then flows through the
components one at a time until they are assigned to output or
a data store
• Batch sequential style
– The processing steps are independent components
– Each step runs to completion before the next step begins
• Pipe-and-filter style
– Emphasizes the incremental transformation of data by successive
components
–

13. Data Flow
Architecture

14. Call-and-Return Style
• Has been the dominant architecture since the start of software
development
• Main program and subroutine style
– Decomposes a program hierarchically into small pieces (i.e., modules)
– Typically has a single thread of control that travels through various
components in the hierarchy
• Remote procedure call style
– Consists of main program and subroutine style of system that is
decomposed into parts that are resident on computers connected via
a network
– Incurs a finite communication time between subroutine call and
response

15. 25
Call-and-Return Style
Main module
Subroutine A
Subroutine B
Subroutine A-1 Subroutine A-2
Physical layer
Data layer
Network layer
Transport layer
Application layer
Class W
Class V
Class Z
Class X Class Y

16. Layered
Architecture

17. Analyzing Architectural Design
1.Collect scenarios.
2.Elicit requirements, constraints, and environment
description.
3.Describe the architectural styles/patterns that have been
chosen to address the scenarios and requirements:
 Logical view
 process view
 Implementation view
 Deployment view

18. Thank You