Information Systems - Ch. 3: System Development Basics

Fundamentals of Information Systems - Chapter 3: Basics of System Development

• Businesses utilize managers and employees across all functional areas working together with business information systems.
• This collaboration aids in the development, and often the leadership, of these systems.

Business System Concepts

• The term "system" is widely used to give contemporary significance to processes and items.
• Examples include exercise systems, investment systems, delivery systems, information systems, education systems, and computer systems.
• A system is a collection of components working together in an interconnected way towards a shared objective or cause.

Definition of a System

• Systema, a Greek word meaning an organized relationship between functioning units or components is the source of the term "system."
• Systems exist in order to achieve specific objectives.
• Transportation, telephone, accounting, production, and computer systems are examples of systems encountered daily.

Characteristics of a System

• Organization or order within the system
• Interaction among components
• Interdependence of components
• Integration of components
• A central objective that the system aims to achieve

Elements of a System

• Systems analysts usually function in a dynamic setting with constant change, which can include business firms, applications, or computer systems.
• Key elements to consider in reconstructing a system include:
  • Outputs and inputs
  • Processors
  • Control mechanisms
  • Feedback loops
  • The environment in which the system operates
  • Boundaries and interfaces of the system

System Development

• System development is both the art and science of creating man-made systems to meet specific needs.
• It involves problem-solving, utilizing the knowledge base to create solutions tailored to the problem.
• Information systems must continually change as the environment, technology, and competition evolve.
• These changes can range from minor adjustments to major overhauls.
• Sometimes old systems are replaced.

Introduction to System Development

• Companies modify their systems for a variety of reasons, including:
• Responding to changes in business or user needs
• Taking advantage of or adapting to technological changes
• Accommodating improvements in business processes.
• Gaining a competitive edge or lowering costs
• Increasing productivity
• Accommodating growth
• Facilitating downsizing or distributed decision-making
• Integrating incompatible systems
• Replacing aged or unstable systems

Participants in Systems Development

• Systems development is a team effort, which includes:
  • Stakeholders
  • Users
  • Managers
  • System development specialists
  • Support personnel
• The development team determines the objectives for the information system and delivers a system that meets these objectives.

Roles of Participants in Systems Development

• Stakeholders: Individuals or entities who ultimately benefit from the system development project, either directly or through the organization they represent.
• Users: Individuals who regularly interact with the system.
• Systems Analyst: Professional who specializes in analyzing and designing business systems.
• Programmer: Specialist responsible for modifying or developing programs to meet user requirements.

Systems Development Life Cycle (SDLC)

• The systems development process is referred to as SDLC because its activities are ongoing.
• Timelines and deadlines are created as each system is built until the system is installed and approved.
• The system is maintained and reviewed throughout its life.
• A new project begins if a system requires major improvements beyond maintenance, needs replacement due to new technology, or if the organization's IS needs change significantly, restarting the cycle.

Traditional Systems Development Life Cycle

• Traditional systems, from small computer programs to major projects.
• Approaches typically consist of five common phases:
  • Investigation
  • Analysis
  • Design
  • Implementation
  • Maintenance and Review

Systems Investigation

• Potential problems and opportunities are pinpointed and analyzed relative to the business goals.
• The goal is to answer: "What is the problem, and is it worth solving?"
• The primary outcome is a well-defined development project with developed business problems or opportunity statements, allocated resources, and a recommendation for systems analysis.

Initiating Systems Investigation

• Organizations use a process for starting systems development due to the significant time and effort required for system development requests, beginning with system investigation.

Systems Request Form

• It is completed by someone in the IS department to initiate systems investigation.
• The form includes:
  • Problems or opportunities with the system
  • Objectives of the systems investigation
  • System overview
  • Costs and benefits

Feasibility Analysis

• A key step which assesses:
  • Technical Feasibility: availability of hardware, software, and components to solve the problem.
  • Economic Feasibility: determines project’s financial sense and if the projected benefits outweigh the costs
  • Operational Feasibility: ability to be put into action or operation
  • Legal Feasibility: determination of laws and regulations that may prevent or constrain development project.
  • Schedule Feasibility: Project completion in reasonable time.

Systems Analysis

• Determines what an information system must do to solve a problem
• Involves investigating existing systems to identify strengths, weaknesses, and areas to improve
• The main result is a list of needs and their priorities

Activities in Systems Analysis: Data Collection

• The objective is to gather more details regarding the issues or requirements that have been identified in the system investigation report.
• Data collection tools include:
  • Structured interviews
  • Questionnaires
  • Documentation
  • Observation

Activities in Systems Analysis: Data Analysis

• Entails the manipulation of collected data for systems analysis.
• It involves using data-flow diagrams and entity-relationship diagrams.
• Common data analysis tools, and techniques are:
  • Application flowcharts
  • Grid charts
  • Computer-aided software engineering tools (CASE)
  • object-oriented approach

Activities in Systems Analysis: Data Modeling

• Typically carried out through entity-relationship (ER) diagrams.

Activities in Systems Analysis: Activity Modeling

• Accomplished by using data-flow diagrams.
• Dataflow diagrams (DFD) model objects, associations, and activities by describing how data flows in an environment where various objects are held.

Systems Design

• Focuses on how the information system will achieve the problem solution.
• Key outcome is a technical design
• Describes the intended system in terms of system components, interfaces and their relations
• Details system outputs, inputs, and user interfaces
• Specifies hardware, software, database, telecommunications, personnel, and procedure components.

Two Key Aspects of Systems Design

• Logical design: Describes a system’s functional requirements.
• Physical design: Details the system components and needed to implement the logical design.

Systems Implementation

• Involves creating or acquiring components from the system design
• Combining them
• Putting the new or improved system into use.
• A key part is to train the users.
• Results in an installed, working information system that addresses the business requirements for which it was created.
• Can involve phasing out or removing old systems, which can present challenges for existing users if those systems are free.

Typical Steps in Systems Implementation

• Hardware and software acquisition
• User preparation
• Installation
• Testing

Types of Testing

• Unit Testing: Testing individual programs
• System Testing: Testing the whole system of programs
• Integration Testing: Testing related systems together
• Acceptance Testing: Tests required by the user

Systems Maintenance and Review

• Designed for ensuring the system runs as expected; necessary to adjust and update the system to deal with new business needs.
• Modifications arise from user needs and technological advances.