Question 1
Using architecture of a house or building as a metaphor, draw comparisons with software architecture. What are the similarities and differences?
Similarities:
1. Blueprints/Design Plans: Both software and building architectures begin with
detailed blueprints or design plans that outline the structure, components, and
interactions of the system. These blueprints serve as a roadmap for construction.
2. Structural Components: Just as buildings have structural components like walls,
floors, and roofs, software systems have components such as modules, classes,
and interfaces that form the foundation of the system.
3. Functionality and Purpose: Both architectures are designed to fulfill specific
functions or purposes. A building is constructed to provide shelter,
accommodation, or workspace, while software is developed to perform certain
tasks or provide services.
4. Scalability and Flexibility: Both architectural designs aim to accommodate
future changes and expansions. A well-designed building or software system
should be scalable and flexible enough to adapt to evolving needs and
requirements.
5. Aesthetics and User Experience: Both architectures consider aesthetics and user
experience. In buildings, architectural design affects factors like layout,
aesthetics, and usability. Similarly, in software, the user interface (UI) design and
user experience (UX) play crucial roles in usability and satisfaction.
Differences:
1. Physical vs. Virtual: The most obvious difference is that building architecture
deals with physical structures and materials, whereas software architecture is
concerned with virtual components and code.
2. Construction Process: Building architecture involves physical construction
processes like excavation, framing, and finishing, whereas software architecture is
more about design, coding, testing, and deployment.
3. Maintenance and Upkeep: Buildings require ongoing maintenance, repairs, and
renovations to ensure structural integrity and safety. Software systems also
require maintenance, but it involves updating code, fixing bugs, and enhancing
features.
4. Cost and Resources: The cost and resources involved in building architecture,
such as materials, labor, and land, differ significantly from those in software
architecture, which primarily involve human capital and computing resources.
5. Lifecycle and Evolution: Building architecture tends to have a longer lifecycle,
with renovations or major changes occurring less frequently. In contrast, software
architecture often evolves rapidly, with updates, patches, and new versions
released frequently to address changing requirements and technologies.
Question 2
Briefly describe each of the four elements of the design model.
The design model consists of five key elements, each playing a crucial role in the
development of software systems:
1. Data/Class Design: This element focuses on modeling the data structures and
classes required by the software. It involves identifying the types of data that need
to be stored and manipulated within the system and designing appropriate data
structures and class hierarchies to represent them. Data/Class design ensures that
data is organized efficiently and can be accessed and modified as needed by the
software.
2. Architectural Design: Architectural design defines the overall structure and
organization of the software system. It involves identifying the major components
or modules of the system, specifying their interactions and dependencies, and
determining how they will be deployed and executed within the system
environment. Architectural design provides a high-level view of the system's
structure, guiding the implementation and integration of its various components.
3. Interface Design: Interface design focuses on defining the external interfaces of
the software system. This includes user interfaces, which allow users to interact
with the system, as well as interfaces with other software systems or hardware
devices. Interface design ensures that the system is easy to use, integrates
seamlessly with other systems, and provides clear and consistent communication
channels for data exchange.
4. Component-Level Design: Component-level design involves detailed design and
specification of individual software components or modules. It defines the
internal structure and behavior of each component, including its data structures,
algorithms, and interfaces. Component-level design ensures that each module
performs its designated functions correctly and efficiently, and can be easily
integrated into the larger system.
5. Deployment-Level Design: Deployment-level design addresses the deployment
and configuration of the software system within its target environment. It involves
specifying how the system will be installed, configured, and distributed across
various hardware platforms and network environments. Deployment-level design
ensures that the software can be effectively deployed and operated in real-world
settings, meeting performance, reliability, and scalability requirements.
Question 3
Select a few diagrams from the design model. For each diagram, describe the possible sources of its contents from the analysis model.
Class Diagram:
Possible Sources: The class diagram in the design model could be derived from the
analysis model's class diagram. It refines and extends the classes identified during the
analysis phase, adding more details such as attributes, methods, and relationships
between classes. Additionally, the design class realizations identified during the analysis
phase may be further refined and detailed in the design class diagram.
Component Diagram:
Possible Sources: The component diagram may draw its contents from various sources in
the analysis model. It could represent the decomposition of high-level system
components identified during analysis into smaller, more manageable modules. These
components may correspond to subsystems, packages, or other architectural elements
identified during the analysis phase. Additionally, the component diagram may depict the
dependencies and interactions between these components, which may have been inferred
from the analysis model's behavior diagrams or use case scenarios.
Deployment Diagram:
Possible Sources: The deployment diagram typically reflects the physical deployment of
software components onto hardware nodes in a distributed system. The contents of this
diagram may originate from the analysis model's description of the target environment
and infrastructure requirements. It may specify the mapping of software components to
hardware nodes, networks, and other physical resources. Additionally, deployment
constraints and considerations identified during the analysis phase, such as performance
requirements or security constraints, may influence the design decisions reflected in the
deployment diagram.
Question 4
Present two or three examples of applications for each of the architectural styles given in Lecture 6.
Data-Centered Architecture:
- Examples:
- Online Banking Systems: These systems typically revolve around managing and
processing large volumes of customer data, such as account information, transaction
history, and user profiles. The architecture focuses on efficient data storage, retrieval, and
manipulation to ensure the integrity and security of financial information.
- Customer Relationship Management (CRM) Systems: CRM systems centralize
customer-related data, including contact information, purchase history, and interactions.
The architecture emphasizes data accessibility and consistency across different modules,
enabling seamless customer interactions and personalized services.
- Inventory Management Systems: These systems track and manage inventory levels,
orders, and supply chain activities. The architecture prioritizes efficient data management
to ensure real-time visibility into inventory levels, optimize stock replenishment, and
minimize stockouts.
Data Flow Architecture:
- Examples:
- Online Marketplace Platforms: These platforms facilitate transactions between
buyers and sellers, involving multiple data flows such as product listings, orders,
payments, and shipping notifications. The architecture focuses on orchestrating these data
flows efficiently while ensuring data integrity, security, and scalability.
- Content Management Systems (CMS): CMS platforms enable users to create,
manage, and publish digital content, including articles, images, videos, and documents.
The architecture supports content creation, editing, and publishing workflows, with data
flows for content ingestion, storage, retrieval, and presentation.
- Automated Manufacturing Systems: These systems control the flow of materials,
parts, and information in manufacturing processes, orchestrating activities such as
production scheduling, inventory management, and quality control. The architecture
emphasizes the coordination of data flows between different production stages and
equipment to optimize efficiency and minimize downtime.
Call and Return Architecture:
- Examples:
- Web-Based E-Commerce Applications: E-commerce applications follow a call and
return architecture, where client requests (calls) trigger server-side processing (return) to
generate responses. These applications handle user interactions such as browsing
products, adding items to the cart, and completing checkout processes.
- Enterprise Resource Planning (ERP) Systems: ERP systems integrate various
business processes and functions across an organization, including finance, human
resources, supply chain, and customer relationship management. The architecture
involves invoking specific modules or services (calls) to perform tasks such as payroll
processing, inventory management, and order fulfillment.
- Online Ticket Booking Systems: Ticket booking systems handle user requests for
booking tickets to events, flights, or shows. The architecture processes user inputs (calls),
validates availability and pricing, and confirms bookings (return) by interacting with
backend databases and external services.
Question 5
Explain the terms architectural style, architectural pattern, and framework in relation to software architecture.
Architectural Style:
An architectural style refers to a set of principles or guidelines that shape the overall
structure, organization, and behavior of a software system. It represents a fundamental
design choice that dictates how components and modules within the system interact and
communicate with each other. Architectural styles often embody common design
decisions and trade-offs, influencing aspects such as system scalability, performance,
maintainability, and flexibility.
Example: Client-Server Architecture, where client devices (e.g., web browsers, mobile
apps) interact with centralized servers to request and receive services or data. This style
emphasizes the separation of concerns between client-side presentation and server-side
processing.
Architectural Pattern:
An architectural pattern is a reusable solution to a recurring design problem within a
specific context. It provides a high-level template or blueprint for organizing the structure
and behavior of software systems, guiding the arrangement of components, modules, and
interactions to achieve desired architectural qualities. Architectural patterns capture best
practices and proven design strategies, offering guidance on system decomposition,
communication mechanisms, and overall system organization.
Example: Model-View-Controller (MVC) Pattern, which separates the presentation,
business logic, and data access layers of an application. This pattern promotes
modularity, maintainability, and testability by decoupling user interfaces (Views) from
application logic (Controllers) and data storage (Models).
Framework:
In software architecture, a framework is a pre-established structure or skeleton that
provides a foundation for building specific types of software applications. It typically
consists of reusable components, libraries, and design patterns tailored to address
common requirements or domain-specific challenges. Frameworks offer developers a
standardized way to create, extend, and customize software solutions by encapsulating
essential functionalities, enforcing design principles, and providing extension points for
application-specific logic.
Example: Spring Framework for Java, which offers comprehensive support for
developing enterprise-scale Java applications. It provides modules for dependency
injection, aspect-oriented programming, transaction management, and other cross-cutting
concerns, enabling developers to focus on business logic while leveraging built-in
infrastructure components.