System Analysis: Modeling and Fact-Finding

• This chapter is about requirements modeling techniques and team-based methods to visualize and document new systems, as well as system requirements and fact-finding.
• Fact-finding techniques include interviewing, documentation review, observation, surveys and questionnaires, sampling, and research.

Systems Analysis Activities

• The systems analysis phase tasks include requirements modeling, data and process modeling, object modeling, and development strategies.
• Requirements modeling involves fact-finding to describe outputs, inputs, processes, performance, and security.

The Systems Analysis skills include

• Analytical skills
• Interpersonal skills

Team-Oriented Methods and Techniques

• Joint application development (JAD)
• Rapid application development (RAD)

Joint Application Development

• JAD requires user involvement.
• Users have a vital stake in an information system and should fully participate.
• Successful systems must be user-oriented and involve users.
• A JAD team approach is a strategy for user involvement.

JAD Advantages

• Key users can effectively participate.
• More accurate system requirements, better understanding of common goals, and a stronger commitment to the success of the new system may result.

JAD Disadvantages

• It can be expensive and cumbersome if the group is too large relative to the size of the project.

Rapid Application Development

• RAD is a team-based approach to speed up the development of information systems and produce usable information system.
• Relies heavily on prototyping and user involvement.
• The process continues until the system is completely developed and users are satisfied.

Similarities Between JAD and RAD

• A group approach is used.

Differences Between JAD and RAD

• The end product of JAD is a requirements model.
• The end product of RAD is a brand new IS.

RAD Advantages

• Systems can be developed more quickly with significant cost savings

RAD Disadvantages

• RAD stresses the mechanics of the system and does not emphasize the company's strategic business needs.
• Less time to develop quality, consistency, and design standards might be allowed.

Modeling Tools and Techniques

• CASE Tools (computer-aided system engineering)
• CASE tools document business functions and processes.
• CASE tools develop graphical models and provide an overall framework for IS development.
• Functional Decomposition Diagrams (FDD)
• FDD are also called structure charts and provide top-down representation of a function or process.
• Data Flow Diagrams (DFD) show how the system stores, processes and transforms data.
• Unified Modeling Language (UML)
• UML visualizes and documents software systems design.
• UML uses object-oriented design concepts.
• UML provides graphical tools, such as use case diagrams and sequence diagrams.
• Use case diagrams visually represent the interaction between users and the IS and shows how the user becomes an Actor.
• Sequence diagrams show the timing of interactions between objects.

System Requirement Definition

• A system requirement is a characteristic that must be included in an IS to satisfy business requirements and be acceptable to users.
• There are five general categories of System requirements: outputs, inputs, processes, performance, and controls.

Fact-Finding Overview

• The first step is to identify the information needed.
• A fact-finding plan should be developed.

Fact-Finding Questions

• Business functions the current system supports
• Strategic objectives and business requirements that must be supported by the new system
• Benefits and TCO of the proposed system
• Transactions the system will process
• Information users and managers need from the system
• Whether the new system must interface with legacy systems
• Procedures that could be eliminated by business process reengineering
• Potential security issues
• Acceptable risks
• Budget and timeline constraints that will affect system development

Key Questions for Fact-Finding

• Answers should be given to questions of "who, what, where, when, and how?"
• The answer to "why?" is also important.

Fact-Finding Interviews

• Systems analysts spend time talking with people, especially conducting interviews.
• Interview: The steps are to determine the people to interview, establish objectives, develop questions, prepare, conduct, document, and evaluate.

Observation

• Observation allows the analyst to see the system in action and gives additional perspective and better understanding of the system procedures.

Questionnaires and Surveys

• When designing a questionnaire, the most important rule is to make sure collected questions collect the right data in a form for further fact-finding.

Sampling

• Sampling means collecting examples of actual documents.
• The main objective of a sample is to accurately represent the overall population.
• Systematic sample, Stratified sample, and Random sample are used.

Research

• Used to gather information in the Internet, IT magazines, and books to obtain background, technical material, and news about industry trends and developments.
• Site visits are used when visiting a location.

Interviews Versus Questionnaires

• Interviews are more personal
• Questionnaires give many people the opportunity to provide input and suggestions

Brainstorming

• Is a method of generating ideas on a topic
• Structured brainstorming vs unstructured brainstorming

Documentation

• Documentation involves Software Tools, CASE Tools, Productivity Software (word processing, spreadsheets, db applications, and presentation graphics programs)
• Histograms are also used.

Logical design is the translation of

• Business user requirements into a system model
• The model depicts only the business requirements and not any possible technical design or implementation of those requirements
• Common words: conceptual design and essential design

System model

• Picture of a system that represents reality or a desired reality
• System models facilitate improved communication between users/analysts/designers/builders.

Explore system analysis, and requirements modeling techniques. Learn about fact-finding, team-oriented methods like JAD and RAD, and essential analytical and interpersonal skills for system development. Understand user involvement.