ISM 301 Physical Architecture Layer Design PDF

Ch11: Physical Architecture Layer Design ISM 301 SDLC Idea Drawing Blueprint Construction Planning Analysis Development Implementation Unified Process  Physical Architecture Layer This refers to the hardware, software, and network setup for an information system. The...

Ch11: Physical Architecture Layer Design ISM 301 SDLC Idea Drawing Blueprint Construction Planning Analysis Development Implementation Unified Process  Physical Architecture Layer This refers to the hardware, software, and network setup for an information system. The design considers non-functional requirements like performance, security, and operational needs. Major Components of the architecture: Data Storage- Data required to support the application. (Structural Model-Class diagram) Data Access Logic- Data access and manipulation layer. (SQL) Application Logic- Logic in the functioning of the application. (Activity Diagrams/Sequence diagrams) Presentation Logic- HCI Layer. (User Interface)  Types of Systems Architecture Server-Based: All functions (data storage, processing, presentation) occur on one server. This type of setup is suitable for simple setups but can become overloaded with high demand. Client-Based: Tasks are handled by client computers while the server mainly stores data. It works well for small networks but can cause Server-Based Architecture Client-Based Architecture network overload with high data transfers. Client-Server: Most common today, with tasks shared between clients and servers, allowing for better scalability and reliability. Middleware is a type of system software designed to translate between different software. The client software communicates with the middleware, which can reformat the message into a standard language that can be understood by the middleware assisting the server software. Client-Server Architecture  Client-Server Tiers Two-Tiered: Simplest form where the client handles user interface, and the server manages data. Three-Tiered: Adds an application server Two-Tiered Three-Tiered between the client and database server, commonly used for more complex, web- based applications. N-Tiered: Distributes functions across multiple servers for large-scale systems, improving load balance but requiring more network bandwidth. N-Tiered  New Developments Cloud Computing: Thinking IT as a utility or commodity. Essentially, it is a client-server architecture where the server is in the “cloud”, and the client is on the desktop. Divided into IaaS (Infrastructure as a Service), PaaS (Platform as a Service), and SaaS (Software as a Service). It offers flexible, scalable resources managed over the Internet but comes with challenges like data security and vendor dependency. Ubiquitous Computing & IoT (Internet of Things): Integrates computing into everyday objects (like smart devices) to communicate and automate tasks. Raises issues around privacy, security, and the need for an advanced network infrastructure. Green IT: Focuses on reducing the environmental impact of technology. Includes practices like recycling old electronics, using energy-efficient hardware, and moving to cloud storage to reduce the carbon footprint of data centers.  Design Process: Selecting Architecture The choice of architecture (server-based, client-based, or client-server) depends on the organization’s current setup and resources. Factors to consider: Infrastructure Compatibility: New systems often need to fit within the existing IT environment, so compatibility with current hardware and software is essential. Cost: Cost comparisons between architectures are critical. Client-server architectures are often preferred for scalability and cost-effectiveness, while server-based systems might be chosen when strict security or control is needed. Security: Architectures differ in control levels. Server-based architectures can offer centralized security, whereas client-server models need robust measures to secure data across multiple points. Scalability: the ability to increase or decrease the capacity of the computing infrastructure in response to changing capacity needs. Client-server architectures are typically the most scalable, allowing organizations to add more servers or clients as demand grows.  Design Process: Infrastructure Design Network Model and Deployment Diagrams Network Model: Shows how the system’s components (e.g., clients, servers, networks) connect across locations. Purpose: Helps the team understand the system’s complexity, cost, and setup across different geographic locations. Components: Typically includes clients, servers, network equipment, and any external connections or systems, like cloud providers. Deployment Diagram: A detailed view of the physical architecture layer, showing specific hardware and software deployment. Nodes: Each physical device in the network (e.g., servers, client computers, routers). Artifacts: Software or system components assigned to each node. Communication Paths: Defines the connections between nodes, showing how they communicate, like LAN, internet, or specific protocols (e.g., TCP/IP). Example: Deployment Diagrams for a Hospital Appointment Management System  Design Process Hardware and Software Specification: Purpose: To create a document that outlines the requirements for purchasing or configuring the system’s physical components. Steps: Define Software Needs: Specify the operating system, database, and any additional applications (e.g., security software) for each component. Hardware Requirements: Detail the hardware specifications for each device, like memory, processing power, and storage capacity. Vendor Selection: After specifying needs, organizations may use a comparison matrix to evaluate and select vendors, focusing on criteria like CPU speed, RAM, reliability, and network compatibility. Example: Hardware and Software Specification  Non-Functional Requirements Operational Requirements: Describe the environments in which the system must function and any future changes. Technical Environment: Specifies required hardware, software, and networks (e.g., “The system must operate on Windows and Linux platforms”). System Integration: Determines compatibility with other systems (e.g., “Must integrate with the main inventory database”). Portability: Flexibility for future changes, such as moving from desktop to mobile devices (e.g., “Must operate on mobile platforms in the future”). Maintainability: Plans for anticipated business changes (e.g., “Should support additional manufacturing plants with minimal reconfiguration”).  Non-Functional Requirements Performance Requirements: Focus on system efficiency and reliability. Speed: The required response time and transaction speed (e.g., “Transactions must process in under 7 seconds”). Capacity: The maximum number of users and data volume (e.g., “Support up to 200 simultaneous users during peak times”). Availability and Reliability: Expected uptime and backup needs (e.g., “System must be available 99% of the time with monthly downtime under 6 hours”).  Non-Functional Requirements Security Requirements: Ensures data integrity and limits access to authorized users. System Value: Estimated business value of the system and its data. Considers the financial or operational impact of data loss (e.g., “System outages cost approximately $50,000 per hour”). Access Control: Defines which users can view, modify, or delete data (e.g., “Only managers can update inventory records”). Encryption and Authentication: Defines what data will be encrypted where and whether authentication will be needed for user access (e.g., “Data encrypted during external transfers”). Virus Control: Protection against malware (e.g., “All uploaded files scanned for viruses”).  Non-Functional Requirements Cultural and Political Requirements: Factors that address regional, legal, and social issues. Language and Localization: Support for various languages or date formats. Privacy Regulations: Compliance with privacy laws like GDPR. Access Based on Geographic Restrictions: Limitations on where and when data can be accessed due to regional laws or company policy. End of Chapter Thank You