fundamentals of information systems, second edition 1 systems development

Fundamentals of Information Systems, Second Edition

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Systems Development


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Principles and Learning Objectives

• Effective systems development requires a team effort of stakeholders, users, managers, systems development specialists, and various support personnel, and it starts with careful planning.


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• Systems development often uses different approaches and tools such as traditional development, prototyping, rapid application development, end-user development, computer-aided software engineering, and object-oriented development to select, implement, and monitor projects.


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• Systems development starts with investigation and analysis of existing systems.


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• Designing new systems or modifying existing ones should always be aimed at helping an organization achieve its goals.


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• Maintenance and review add to the useful life of a system but can consume large amounts of resources, so they benefit from the same rigorous methods and project management techniques applied to systems development.


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An Overview of Systems Development


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Top Uses for New Systems in Various Industries


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Participants in Systems Development


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Information Systems Planning


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Systems Development Life Cycles and Approaches


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The Traditional SDLC


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Prototyping is an Iterative Approach to Systems Development


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Rapid Application Development (RAD)

• Employs tools, techniques, and methodologies designed to speed application development.

• Joint Application Development (JAD) - RAD makes extensive use of this for data collection and requirements analysis.


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Advantages and Disadvantages of RAD


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Use of Project Management Tools

• Project schedule

• Project milestone

• Project deadline

• Critical path

• Program Evaluation and Review Technique (PERT)

• Gantt chart


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Gantt Chart


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Selected Project Management Software


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Computer-Aided Software Engineering (CASE) Tools

Automate many of the tasks required in a systems development effort and enforce adherence to the SDLC, thus instilling a high degree of rigor and standardization to the entire systems development process

• Upper-CASE tools - CASE packages that focus on activities associated with the early stages of systems development.

• Lower-CASE tools - focus on the later stages of systems development and are capable of automatically generating structured program code.

• Integrated-CASE tools - provide links between upper- and lower-CASE packages.


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Object-Oriented Systems Development

• Identify potential problems and opportunities within the organization that would be appropriate for the OO approach

• Define the kind of system users require

• Design the system

• Program or modify modules

• Evaluation by users

• Periodic review and modification


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Use Case Diagram for a Kayak Rental Application


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Systems Development Maturity Based on the Capability Maturity Model (CMM)


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Systems Investigation


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Systems Investigation

• Attempts to answer the following questions:

– What primary problems might a new or enhanced system solve?

– What opportunities might a new or enhanced system provide?

– What new hardware, software, databases, or procedures will improve an existing system?

– What are the potential costs (variable and fixed)? – What are the associated risks?


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Feasibility Analysis


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Systems Investigation Report


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Systems Analysis


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Systems Analysis

• Data collection - seeks additional information about the problems

• Data Analysis - manipulates collected data so that it is usable for the development team


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Internal and External Sources of Data


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The Steps in Data Collection


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Data and Activity Modeling


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Requirements Analysis

• Asking directly• Determining critical success factors (CSFs)• Developing the IS plan


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The Systems Analysis Report

• The report should cover the following:

– The strengths and weaknesses of the existing system from a stakeholder’s perspective

– The user/stakeholder requirements for the new system (also called the functional requirements)

– The organizational requirements for the new system– A description of what the new information system

should do to solve the problem


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Converting Organizational Goals into Systems Requirements


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A Typical Table of Contents for aReport on an Existing System


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Systems Design


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Systems Design

• Logical design - involves planning the purpose of each system element.

• Physical design - refers to how the tasks are accomplished, including how the components work together and what each component does.


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Request for Proposal

One of the most important documents generated during systems development.

• Results in a formal bid that is used to determine who gets a contract for new or modified systems.

• Specifies in detail required resources.


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A Typical Table of Contents for a

Request for Proposal


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Advantages and Disadvantages of Acquisition Options


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Freezing Design Specifications


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A Typical Table of Contents for a Systems Design Report


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Systems Implementation


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Typical Steps in Systems Implementation


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Types of Testing


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Start-up Approaches


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Systems Maintenance and Review


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Systems Maintenance

• Reasons for program maintenance include:

– Changes in business processes– New requests from stakeholders, users, and

managers– Bugs or errors in the program– Technical and hardware problems– Corporate mergers and acquisitions– Government regulations– Change in the operating system or hardware on which

the application runs– Unexpected events, like the terrorist attacks of

September


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Examples of Review Types


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Summary

• Systems development team - consists of stakeholders, users, managers, systems development specialists, and various support personnel.

• Five phases of the traditional SDLC - investigation, analysis, design, implementation, and maintenance and review.

• Systems investigation - designed to assess the feasibility of implementing solutions for business problems.


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Summary

• Systems analysis - the examination of existing systems, which begins once approval for further study is received from management.

• Systems design – purpose is to prepare the detailed design needs for a new system or make modifications to an existing one.

• Systems implementation - to install a system and make everything, including users, ready for its operation.

• Systems maintenance - involves checking, changing, and enhancing the system to make it more useful in obtaining user and organizational goals.

fundamentals of information systems, second edition 1 systems development

Documents

systems development

analysis of existing

traditional development

enduser development

objectoriented development

edition principles

learning objectivesmaintenance

project management techniques