Chapter 11

Chapter 11: Physical Architecture Layer Design

• The physical architecture layer encompasses the hardware, software, and network setup for an information system.
• The design focuses on non-functional requirements like performance, security, and operational needs.
• Key components include data storage (structural model diagrams), data access logic (SQL), application logic (activity diagrams/sequence diagrams), and presentation logic (HCI layer, user interface).

System Development Life Cycle (SDLC)

• SDLC stages include Planning, Drawing Analysis, Blueprint Development, and Implementation.
• Visual components such as a light bulb (Idea), a house (Drawing Analysis), a blueprint (Blueprint Development) and construction tools (Implementation) are described.

Unified Process

• A diagram visualizes the unified process's phases: Inception, Elaboration, Construction, and Transition.
• Different phases are associated with different engineering workflows(Inception- Business Modeling, Design) and supporting workflows.
• Each phase can have iterative processes denoted as i, i+1,j,(j+1),k,(k+1).

Types of Systems Architecture

• Server-Based: All functions (data storage, processing, presentation) occur on a single server, suitable for simple setups.
• Client-Based: Tasks are handled by client computers, storing data on the server; suitable for smaller networks.
• Client-Server: Divides tasks between client and server; enabling better scalability and reliability.
• Middleware, a type of system software, facilitates communication between client and server software.

Client-Server Tiers

• Two-Tiered: A basic model where the client handles user interface, and the server manages data.
• Three-Tiered: Adds an application server between the client and database server; optimized for complex web-based applications.
• N-Tiered: Distributes functions across multiple servers, enhancing load balancing but requiring more network bandwidth for large-scale systems.

New Developments

• Cloud Computing: A client-server architecture where the server is located in the "cloud".
• Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS) are three cloud service categories.
• Ubiquitous Computing & IoT (Internet of Things): Integrates computing functionality into everyday objects like smart devices.
• Increased computing functionality requires advanced network infrastructure.
• Green IT: Focuses on reducing technological environmental impact; includes practices like recycling and efficient hardware.

Design Process: Selecting Architecture

• Architecture selection depends on current resources and organizational setup.
• Infrastructure compatibility and cost factors should be considered when choosing between server-based, client-based, or client-server models.
• Security and scalability are crucial factors in architecture selection.

Design Process: Infrastructure Design

• Network Model and Deployment Diagrams: Illustrate system component connections, complexity, and cost.

• Network models show how components (e.g., clients, servers, networks) connect in various locations.

• Deployment diagrams detail the physical architecture layer, highlighting hardware and software components.

• The diagrams illustrate nodes or components such as software on a piece of equipment or artifacts, like servers, client computers, and routers.

• Diagrams show communication paths between components such as servers, and clients using LAN, internet, specific protocols (e.g., TCP/IP).

Design Process: Hardware and Software Specification

• Defines required hardware and software components for a system.
• Steps include specifying operating systems, database systems, additional applications (security), detailing hardware specs (memory, processing capacity), and choosing vendors.

Non-Functional Requirements

• Operational Requirements: Describe system operational environments and future changes.

  • Technical Environment: Specifying hardware, software, and network requirements.
  • System Integration: Determining system compatibility with other systems.
  • Portability: Ensuring flexibility for future changes, such as adapting devices and platforms.
  • Maintainability: Ensuring support for additional systems and operations.

• Performance Requirements:

  • Speed: Determines required response time.
  • Capacity: Defines maximum users and data volume capacity.
  • Availability and Reliability: Provides expected uptime and data backup.

• Security Requirements:

  • Ensures: Data integrity and limits access to authorized users.
  • System Value: Estimates financial implications and operational disruption related to data losses.
  • Access Control: Defines user access privileges for data modification.
  • Encryption and Authentication: Determines data encryption and authentication requirements.
  • Virus Control: Describes the methods to prevent malware.

• Cultural and Political Requirements:

  • Language and Localization: Considering multilingual or date format requirements.
  • Privacy Regulations: Ensures compliance with relevant regulations.
  • Access Based on Geographic Restrictions: Addressing limitations due to regional laws.

This quiz covers the physical architecture layer of information systems, emphasizing hardware, software, and network configurations. You'll explore the non-functional requirements that ensure good performance and security, as well as key components such as data storage and application logic. Prepare to analyze the stages of System Development Life Cycle and understand the Unified Process phases.