Systems Analysis and Design: Introduction to Information Systems

Fundamental Concepts of Information Systems

  • Definition of a System: A system is defined as a collection of Elements in an Environment such that there is an Interaction among the elements and between the elements and the environment to reach the predefined Goals.

  • Core System Properties:   - Elements: The individual components that make up the system.   - Environment: The surrounding context or space in which the system operates.   - Interaction: The relationship and communication between internal elements and between those elements and the external environment.   - Goals: The predefined objectives that the system is designed to achieve.

  • Temporal Record: This material was referenced on 10/9/2023.

Hierarchical Levels of Meaning

  • Data: Represented as raw facts.

  • Information: Defined as processed data.

  • Knowledge: Defined as the analyzed data.

  • Wisdom: The level associated with decision making.

Information Technology vs. Information Systems

  • An Information Technology (IT): The combination of hardware, software, and services that people use to manage, communicate, and share information.

  • An Information System (IS): A system that uses information technology to provide support for business functions such as human resources, accounting, marketing, and many more. Attributes include:   - Handling of day-to-day tasks.   - Assisting managers in making better decisions.

  • Key Characteristics of an Information System:   - Effective Processing: Efficient handling of data and tasks.   - Effective Management: Strong oversight and administration of system resources.   - Flexibility: The ability of the system to adapt to changes.   - User Satisfaction: Meeting the needs and expectations of those using the system.

Organizational Structure and User Information Needs

  • Typical Organizational Model (Figure 1-20): Intersects business functions with organizational levels.   - Business Functions: Production, Human Resources (HR), IT, Accounting, Marketing, and Sales.   - Organizational Levels:     - Top Managers:       - Tasked with developing long-range strategic plans that define the overall company mission and goals.       - Need information regarding economic forecasts, technology trends, competitive threats, and governmental issues.     - Middle Managers and Knowledge Workers:       - Tasked with providing direction, necessary resources, and performance feedback to supervisors and team leaders.       - Require more detailed information than top-level management.     - Supervisors and Team Leaders:       - Tasked with overseeing operational employees and carrying out day-to-day functions.     - Operational Employees:       - Rely on transaction processing systems to enter and receive the data required to perform their specific jobs.

The Information Technology Department Organization

  • Overview: Depending on company size, an IT department may have separate units or combined teams for specific functions (Figure 1-29).

  • Application Development: Systems are developed by teams consisting of users, managers, and IT staff members.

  • Systems Support and Security: Provides vital protection and maintenance services for the organization.

  • User Support: Provides technical information, training, and necessary support directly to users.

  • Database Administration: Involves data design, management, security, backup, and access systems.

  • Network Administration: Includes hardware and software maintenance, support, and security for the network infrastructure.

  • Web Support: Web support specialists design and construct Web pages, monitor traffic, manage hardware and software, and link Web-based applications to the company’s information systems.

  • Quality Assurance (QA): A team that reviews and tests all applications and systems changes to verify specifications and software quality standards.

The Systems Analyst

  • Primary Role:   - Analysts build a series of models, diagrams, and decision tables.   - They use various descriptive tools and techniques.   - An analyst’s most valuable skill is the ability to listen.   - Effective analysts involve users in every step of the development process.   - They develop project plans and use project management tools to identify tasks and milestones.

  • Knowledge, Skills, and Education:   - Technical Knowledge.   - Communication Skills.   - Business Skills.   - Critical Thinking Skills.   - Flexibility.   - Education.   - Certification.

  • Work Environment: Analysts must know how to use a variety of tools to plan, design, and implement systems. They work in a team environment where input from users, managers, and IT staff contributes to the design.

Systems Development Tools and Techniques

  • Computer-Aided Systems Engineering (CASE) Tools:   - A technique utilizing powerful software (CASE tools) to help analysts develop and maintain systems.   - Provide an overall framework for systems development.   - Capable of generating program code to speed up implementation.   - Increase the probability of high-quality and defect-free software.   - Support design methodologies such as structured analysis and object-oriented analysis.

  • Microsoft Visio: A popular tool used by system analysts to create business-related models.

Systems Development Methods: The SDLC

  • Systems Development Life Cycle (SDLC): A model (Figure 1-25) consisting of five iterative steps, indicated by circular symbols showing interaction among phases.

  • Phase 1: Systems Planning:   - Begins with a systems request describing problems or desired changes.   - Purpose is to perform a preliminary investigation.   - A key part of the preliminary investigation is a feasibility study.

  • Phase 2: Systems Analysis:   - Focuses on building a logical model, including data and process models, of the new system.   - Deliverable: The system requirements document.

  • Phase 3: Systems Design:   - Focuses on creating a physical model that satisfies all documented requirements.   - Includes the design of the user interface.   - Deliverable: The system design specification.   - User involvement is critical during this phase.

  • Phase 4: Systems Implementation:   - The new system is constructed; programs are written and tested.   - The system is installed.   - Deliverable: A completely functioning and documented information system.

  • Phase 5: Systems Support and Security:   - Focuses on maintaining a system that is secure, reliable, maintainable, and scalable.   - Note: Most information systems require significant updates or replacement after several years of operation.

  1. What is the definition of a system?
       - A system is defined as a collection of elements in an environment such that there is an interaction among the elements and between the elements and the environment to reach the predefined goals.

  2. What are the four core system properties?
       - Elements: The individual components that make up the system.
       - Environment: The surrounding context or space in which the system operates.
       - Interaction: The relationship and communication between internal elements and between those elements and the external environment.
       - Goals: The predefined objectives that the system is designed to achieve.

  3. How is data different from information?
       - Data is represented as raw facts, whereas information is defined as processed data.

  4. What does an Information Technology (IT) department generally manage?
       - IT manages the combination of hardware, software, and services used to manage, communicate, and share information.

  5. What are some of the phases in the Systems Development Life Cycle (SDLC)?
       - Phase 1: Systems Planning
       - Phase 2: Systems Analysis
       - Phase 3: Systems Design
       - Phase 4: Systems Implementation
       - Phase 5: Systems Support and Security

  6. What is the role of a Systems Analyst?
       - Analysts build models, diagrams, and decision tables using descriptive tools and techniques while involving users in the development process and utilizing project management tools.

  7. Describe the typical organizational model in relation to information systems.
       - It intersects business functions with organizational levels, where top managers focus on long-term strategic plans, middle managers provide direction and resources, and supervisors oversee operational employees.

  1. What is the purpose of the Systems Planning phase in the SDLC?

  2. What is the difference between knowledge and wisdom in the context of information systems?

  3. How do systems analysts ensure user involvement in the development process?

  4. What role does the database administration play in an IT department?

  5. Why is flexibility considered a key characteristic of an Information System?

  6. What types of information do top managers typically need to make decisions?

  7. Explain what is meant by effective processing in information systems?