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System Development. ทัศนวรรณ ศูนย์กลาง ภาควิชาคอมพิวเตอร์ คณะวิทยาศาสตร์. เนื้อหาบรรยาย. Overview of Information Systems (IS) Information Technology Concepts Business and Specialized IS System Development IS in Business and Society. Components of an IS. Overview. Participants

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system development

System Development

ทัศนวรรณ ศูนย์กลาง

ภาควิชาคอมพิวเตอร์ คณะวิทยาศาสตร์

slide2
เนื้อหาบรรยาย
  • Overview of Information Systems (IS)
  • Information Technology Concepts
  • Business and Specialized IS
  • System Development
  • IS in Business and Society

Components of an IS

overview
Overview
  • Participants
  • Information Systems Planning
    • Investigation and Analysis
    • Design and Implementation
    • Maintenance and Review
  • Tools
an overview of systems development
An Overview of Systems Development
  • Today, users of information systems are involved in their development
  • This chapter will:
    • Help you avoid systems development failures or projects that go over budget

Principles of Information Systems, Ninth Edition

participants in systems development
Participants in Systems Development
  • Development team
    • Determines objectives of the information system
    • Delivers system that meets objectives
  • Project
    • Planned collection of activities that achieves a goal
  • Project manager
    • Responsible for coordinating all people and resources needed to complete a project on time

Principles of Information Systems, Ninth Edition

participants in systems development continued
Participants in Systems Development (continued)
  • Stakeholders
    • People who ultimately benefit from project
  • Users
    • People who will interact with the system regularly
  • Systems development specialists
    • Systems analysts
    • Programmers

Principles of Information Systems, Ninth Edition

slide8

Participants in Systems Development (continued)

Principles of Information Systems, Ninth Edition

initiating systems development
Initiating Systems Development
  • Systems development initiatives
    • Arise from all levels of an organization
    • Can be planned or unplanned
  • Number of reasons for initiating systems development projects
    • Mergers, acquisitions, federal regulations, etc.

Principles of Information Systems, Ninth Edition

information systems planning and aligning corporate and is goals
Information Systems Planning and Aligning Corporate and IS Goals
  • Information systems planning
    • Translating strategic and organizational goals into systems development initiatives
  • Aligning organizational goals and IS goals
    • Critical for successful systems development effort
  • Developing a competitive advantage
    • Creative analysis
    • Critical analysis

Principles of Information Systems, Ninth Edition

slide12

Information Systems Planning

Principles of Information Systems, Ninth Edition

slide13

Aligning Corporate and IS Goals

Principles of Information Systems, Ninth Edition

establishing objectives for systems development
Establishing Objectives for Systems Development
  • Mission-critical systems
    • Play pivotal role in organization’s continued operations and goal attainment
  • Critical success factors (CSFs)
    • Factors essential to success of a functional area of an organization

Principles of Information Systems, Ninth Edition

establishing objectives for systems development continued
Establishing Objectives for Systems Development (continued)
  • Performance objectives
    • Output quality or usefulness
    • Output accuracy
    • Speed at which output is produced
    • Scalability of resulting system
    • Risk of the system

Principles of Information Systems, Ninth Edition

establishing objectives for systems development continued1
Establishing Objectives for Systems Development (continued)
  • Cost objectives
    • Development costs
    • Costs of uniqueness of system application
    • Fixed investments in hardware and related equipment
    • Ongoing operating costs

Principles of Information Systems, Ninth Edition

systems development life cycles
Systems Development Life Cycles
  • The later in the SDLC an error is detected, the more expensive it is to correct
    • Previous phases must be reworked
    • More people are affected

Principles of Information Systems, Ninth Edition

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Systems Development Life Cycles (continued)

Principles of Information Systems, Ninth Edition

systems development life cycles continued
Systems Development Life Cycles (continued)
  • Common systems development life cycles:
    • Traditional
    • Prototyping
    • Rapid application development (RAD)
    • End-user development

Principles of Information Systems, Ninth Edition

the traditional systems development life cycle
The Traditional Systems Development Life Cycle
  • Systems investigation
    • Identifies problems and opportunities and considers them in light of business goals
  • Systems analysis
    • Studies existing systems and work processes to identify strengths, weaknesses, and opportunities for improvement
  • Systems design
    • Defines how the information system will do what it must do to obtain the problem’s solution

Principles of Information Systems, Ninth Edition

the traditional systems development life cycle continued
The Traditional Systems Development Life Cycle (continued)
  • Systems implementation
    • Creates or acquires various system components detailed in systems design, assembles them, and places new or modified system into operation
  • Systems maintenance and review
    • Ensures the system operates as intended
    • Modifies the system so that it continues to meet changing business needs

Principles of Information Systems, Ninth Edition

slide22

The Traditional Systems Development Life Cycle (continued)

Principles of Information Systems, Ninth Edition

slide23

The Traditional Systems Development Life Cycle (continued)

Principles of Information Systems, Ninth Edition

prototyping
Prototyping
  • An iterative approach
  • Operational prototype
    • Prototype that works
    • Accesses real data files, edits input data, makes necessary computations and comparisons, and produces real output
  • Nonoperational prototype
    • A mock-up, or model
    • Includes output and input specifications and formats

Principles of Information Systems, Ninth Edition

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Prototyping (continued)

Principles of Information Systems, Ninth Edition

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Prototyping (continued)

Principles of Information Systems, Ninth Edition

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Prototyping (continued)

Principles of Information Systems, Ninth Edition

slide28
Rapid Application Development, Agile Development, Joint Application Development, and Other Systems Development Approaches
  • Rapid application development (RAD)
    • Employs tools, techniques, and methodologies designed to speed application development
    • Makes extensive use of the joint application development (JAD)
  • Other approaches to rapid development
    • Agile development
    • Extreme programming (XP)

Principles of Information Systems, Ninth Edition

slide29

Rapid Application Development, Agile Development, Joint Application Development, and Other Systems Development Approaches (continued)

Principles of Information Systems, Ninth Edition

the end user systems development
The End-User Systems Development
  • End-user systems development
    • Systems development project in which business managers and users assume the primary effort
    • Disadvantages
      • Some end users do not have the training to effectively develop and test a system

Principles of Information Systems, Ninth Edition

outsourcing and on demand computing
Outsourcing and On-Demand Computing
  • Reduces costs
  • Obtains state-of-the-art technology
  • Eliminates staffing and personnel problems
  • Increases technological flexibility

Principles of Information Systems, Ninth Edition

slide32

Outsourcing and On-Demand Computing (continued)

Principles of Information Systems, Ninth Edition

factors affecting systems development success
Factors Affecting Systems Development Success
  • Successful systems development:
    • Delivers a system that meets user and organizational needs on time and within budget
  • Critical for most systems development projects:
    • Getting users and stakeholders involved

Principles of Information Systems, Ninth Edition

degree of change
Degree of Change
  • Continuous improvement projects
    • High degree of success
    • Relatively modest benefits
  • Managing change
    • Ability to recognize and deal with existing or potential problems

Principles of Information Systems, Ninth Edition

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Degree of Change (continued)

Principles of Information Systems, Ninth Edition

quality and standards
Quality and Standards
  • Quality of project planning
    • Bigger the project, the more likely that poor planning will lead to significant problems
  • Capability Maturity Model (CMM)
    • One way to measure organizational experience

Principles of Information Systems, Ninth Edition

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Quality and Standards (continued)

Principles of Information Systems, Ninth Edition

use of project management tools
Use of Project Management Tools
  • Project schedule
    • Detailed description of what is to be done
  • Project milestone
    • Critical date for completion of a major part of the project
  • Project deadline
    • Date that the entire project is to be completed and operational
  • Critical path
    • Activities that, if delayed, would delay the entire project

Principles of Information Systems, Ninth Edition

use of project management tools continued
Use of Project Management Tools (continued)
  • Program Evaluation and Review Technique (PERT)
    • Creates three time estimates for an activity
      • Shortest possible time
      • Most likely time
      • Longest possible time
  • Gantt chart
    • Graphical tool used for planning, monitoring, and coordinating projects

Principles of Information Systems, Ninth Edition

use of computer aided software engineering case tools
Use of Computer-Aided Software Engineering (CASE) Tools
  • CASE tools
    • Automate many tasks required in a systems development effort
    • Encourage adherence to SDLC
  • Companies that produce CASE tools:
    • Accenture, Microsoft, and Oracle

Principles of Information Systems, Ninth Edition

slide41

Use of Computer-Aided Software Engineering (CASE) Tools (continued)

Principles of Information Systems, Ninth Edition

object oriented systems development
Object-Oriented Systems Development
  • Combines logic of systems development life cycle with power of object-oriented modeling and programming
  • OOSD tasks:
    • Identify potential problems and opportunities that would be appropriate for OO approach
    • Define user requirements

Principles of Information Systems, Ninth Edition

object oriented systems development continued
Object-Oriented Systems Development (continued)
  • OOSD tasks (continued):
    • Design system
    • Program or modify modules
    • User evaluation
    • Periodic review and modification

Principles of Information Systems, Ninth Edition

systems investigation
Systems Investigation
  • What primary problems might a new or enhanced system solve?
  • What opportunities might a new or enhanced system provide?
  • What new hardware, software, databases, telecommunications, personnel, or procedures will improve an existing system or are required in a new system?
  • What are the potential costs (variable and fixed)?
  • What are the associated risks?

Principles of Information Systems, Ninth Edition

initiating systems investigation
Initiating Systems Investigation
  • Systems request form
    • Submitted by someone who wants IS department to initiate systems investigation
    • Information included
      • Problems in or opportunities for system
      • Objectives of systems investigation
      • Overview of proposed system
      • Expected costs and benefits of proposed system

Principles of Information Systems, Ninth Edition

participants in systems investigation
Participants in Systems Investigation
  • Members of development team change from phase to phase
  • Keys to successful investigation teams:
    • Cooperation and collaboration

Principles of Information Systems, Ninth Edition

slide47

Participants in Systems Investigation (continued)

Principles of Information Systems, Ninth Edition

feasibility analysis
Feasibility Analysis
  • Technical feasibility
  • Economic feasibility
  • Net present value
  • Legal feasibility
  • Operational feasibility
  • Schedule feasibility

Principles of Information Systems, Ninth Edition

slide49

Feasibility Analysis (continued)

Principles of Information Systems, Ninth Edition

object oriented systems investigation
Object-Oriented Systems Investigation
  • Object-oriented approach
    • Can be used during all phases of systems development
  • Use case diagram
    • Part of the Unified Modeling Language (UML) that is used in object-oriented systems Development

Principles of Information Systems, Ninth Edition

slide51

Object-Oriented Systems Investigation (continued)

Principles of Information Systems, Ninth Edition

the systems investigation report
The Systems Investigation Report
  • Summarizes results of systems investigation
  • Summarizes the process of feasibility analysis
  • Recommends a course of action
    • Continue on into systems analysis
    • Modify the project in some manner
    • Drop the project
  • Reviewed by steering committee

Principles of Information Systems, Ninth Edition

slide53

The Systems Investigation Report (continued)

Principles of Information Systems, Ninth Edition

systems analysis
Systems Analysis
  • Overall emphasis of analysis:
    • Gathering data on existing system
    • Determining requirements for new system
    • Considering alternatives
    • Investigating feasibility of solutions
  • Primary outcome of systems analysis:
    • Prioritized list of systems requirements

Principles of Information Systems, Ninth Edition

general considerations
General Considerations
  • Steps of a formalized analysis procedure:
    • Assembling participants for systems analysis
    • Collecting data and requirements
    • Analyzing data and requirements
    • Preparing a report on existing system, new system requirements, and project priorities

Principles of Information Systems, Ninth Edition

participants in systems analysis
Participants in Systems Analysis
  • Includes members of the original investigation team
  • Systems analysis team develops:
    • List of objectives and activities
    • Deadlines
    • Statement of resources required
    • Major milestones

Principles of Information Systems, Ninth Edition

data collection
Data Collection
  • Identifying sources of data
    • Internal and external sources
  • Collecting data
    • Interviews
    • Direct observation
    • Questionnaires

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slide58

Identifying Sources of Data

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slide59

Collecting Data

Principles of Information Systems, Ninth Edition

data analysis
Data Analysis
  • Data modeling
  • Activity modeling
  • Application flowcharts
  • Grid charts
  • CASE tools

Principles of Information Systems, Ninth Edition

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Data Analysis (continued)

Principles of Information Systems, Ninth Edition

requirements analysis
Requirements Analysis
  • Determination of user, stakeholder, and organizational needs
  • Techniques:
    • Asking directly
    • Critical success factors (CSFs)
    • IS plan
    • Screen and report layout
    • Requirements analysis tools

Principles of Information Systems, Ninth Edition

slide63

Requirements Analysis (continued)

Principles of Information Systems, Ninth Edition

object oriented systems analysis
Object-Oriented Systems Analysis
  • Identify problems or potential opportunities
  • Identify key participants and collect data
  • With the OO approach a class is used to describe different types of objects

Principles of Information Systems, Ninth Edition

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Object-Oriented Systems Analysis (continued)

Principles of Information Systems, Ninth Edition

the systems analysis report
The Systems Analysis Report
  • Elements:
    • Strengths and weaknesses of existing system from a stakeholder’s perspective
    • User/stakeholder requirements for new system
    • Organizational requirements for new system
    • Description of what new information system should do to solve the problem

Principles of Information Systems, Ninth Edition

slide67

The Systems Analysis Report (continued)

Principles of Information Systems, Ninth Edition

systems design
Systems Design
  • Answers the question:
    • How will the information system solve a problem?
  • Results in a technical design that:
    • Details system outputs, inputs, and user interfaces
    • Specifies hardware, software, databases, telecommunications, personnel, and procedures
    • Shows how these components are related

Principles of Information Systems, Ninth Edition

logical and physical design
Logical and Physical Design
  • Logical design
    • Describes functional requirements of a system
  • Physical design
    • Specifies the characteristics of the system components necessary to put the logical design into action

Principles of Information Systems, Ninth Edition

object oriented design
Object-Oriented Design
  • Using the OO approach:
    • You can design key objects and classes of objects in the new or updated system
    • Process includes considering the problem domain, the operating environment, and the user interface
  • During design phase consider the sequence of events that must happen for the system to function correctly

Principles of Information Systems, Ninth Edition

slide71

Object-Oriented Design (continued)

Principles of Information Systems, Ninth Edition

interface design and controls
Interface Design and Controls
  • System characteristics:
    • Sign-on procedure
    • Interactive processing
    • Help facility
    • Lookup tables
    • Restart procedure

Principles of Information Systems, Ninth Edition

slide73

Interface Design and Controls (continued)

Principles of Information Systems, Ninth Edition

slide74

Interface Design and Controls (continued)

Principles of Information Systems, Ninth Edition

design of system security and controls
Design of System Security and Controls
  • Preventing, detecting, and correcting errors
  • Disaster planning and recovery
    • Disaster planning
    • Disaster recovery
  • Systems controls
    • Closed shops
    • Open shops
    • Deterrence controls

Principles of Information Systems, Ninth Edition

environmental design considerations
Environmental Design Considerations
  • Environmental design
    • Also called green design
    • Involves systems development efforts that slash power consumption, require less physical space, and result in systems that can be disposed in a way that doesn’t negatively affect the environment

Principles of Information Systems, Ninth Edition

generating systems design alternatives
Generating Systems Design Alternatives
  • Request for proposal (RFP)
    • Document that specifies required resources such as hardware and software in detail
  • Financial options:
    • Purchase, lease, or rent
  • Evaluating and selecting a systems design
    • Preliminary evaluation
    • Final evaluation

Principles of Information Systems, Ninth Edition

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Generating Systems Design Alternatives (continued)

Principles of Information Systems, Ninth Edition

evaluation techniques
Evaluation Techniques
  • Group consensus
  • Cost/benefit analysis
  • Benchmark tests
  • Point evaluation

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Evaluation Techniques (continued)

Principles of Information Systems, Ninth Edition

slide81

Evaluation Techniques (continued)

Principles of Information Systems, Ninth Edition

freezing design specifications
Freezing Design Specifications
  • User agrees in writing that the design is acceptable
  • Other organizations:
    • Allow or even encourage design changes

Principles of Information Systems, Ninth Edition

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Freezing Design Specifications (continued)

Principles of Information Systems, Ninth Edition

the contract
The Contract
  • Vendors provide standard contracts to protect themselves
  • Typically, the request for proposal becomes part of the contract

Principles of Information Systems, Ninth Edition

the design report
The Design Report
  • Primary result of systems design
  • Reflects decisions made and prepares the way for systems implementation

Principles of Information Systems, Ninth Edition

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The Design Report (continued)

Principles of Information Systems, Ninth Edition

systems implementation
Systems Implementation
  • Includes:
    • Hardware acquisition
    • Programming and software acquisition or development
    • User preparation
    • Hiring and training of personnel
    • Site and data preparation
    • Installation, testing, start-up, and user acceptance

Principles of Information Systems, Ninth Edition

acquiring software make or buy
Acquiring Software: Make or Buy?
  • Make-or-buy decision
    • Whether to obtain software from external or internal sources
  • Externally acquired software and Software as a Service (SaaS)
    • Commercial off-the-shelf (COTS) development process
  • In-house developed software
    • CASE and object-oriented approaches
    • Cross-platform development
    • Integrated development environment

Principles of Information Systems, Ninth Edition

acquiring database and telecommunications systems
Acquiring Database and Telecommunications Systems
  • Databases
    • A blend of hardware and software
  • Virtual databases and database as a service (DaaS)
    • Popular ways to acquire database capabilities

Principles of Information Systems, Ninth Edition

user preparation
User Preparation
  • Readying managers, decision makers, employees, other users, and stakeholders for new systems
  • Important, but often ignored area of systems implementation

Principles of Information Systems, Ninth Edition

is personnel hiring and training
IS Personnel: Hiring and Training
  • Eventual success of any system depends on how it is used by the IS personnel within the organization
  • Training programs should be conducted for the IS personnel who will be using the computer system
    • More detailed than user training in the technical aspects of the systems

Principles of Information Systems, Ninth Edition

site preparation
Site Preparation
  • Preparation of the location of a new system
  • Larger systems may require special equipment
  • Developing IS sites that are energy efficient is important

Principles of Information Systems, Ninth Edition

data preparation
Data Preparation
  • Also called data conversion
  • Ensuring all files and databases are ready to be used with new computer software and systems

Principles of Information Systems, Ninth Edition

installation
Installation
  • Process of physically placing computer equipment on the site and making it operational
  • Normally, manufacturer is responsible for installing computer equipment
  • Someone from the organization (usually IS manager) should oversee the process

Principles of Information Systems, Ninth Edition

testing
Testing
  • Unit testing
  • System testing
  • Volume testing
  • Integration testing
  • Acceptance testing
  • Alpha testing
  • Beta testing

Principles of Information Systems, Ninth Edition

start up
Start-Up
  • Process of making the final tested information system fully operational
  • Approaches
    • Direct conversion (plunge, direct cutover)
    • Phase-in approach (piecemeal)
    • Pilot start-up
    • Parallel start-up

Principles of Information Systems, Ninth Edition

user acceptance
User Acceptance
  • Formal agreement signed by user that states that a phase of installation or the complete system is approved
  • Legal document that removes or reduces IS vendor’s liability

Principles of Information Systems, Ninth Edition

systems operation and maintenance
Systems Operation and Maintenance
  • Systems operation
    • Use of a new or modified system
  • Systems maintenance
    • Checking, changing, and enhancing the system to make it more useful in achieving user and organizational goals

Principles of Information Systems, Ninth Edition

reasons for maintenance
Reasons for Maintenance
  • Changes in business processes
  • New requests from stakeholders, users, and managers
  • Bugs or errors in program
  • Technical and hardware problems
  • Corporate mergers and acquisitions
  • Government regulations

Principles of Information Systems, Ninth Edition

types of maintenance
Types of Maintenance
  • Slipstream upgrade
    • Usually requires recompiling all the code
  • Patch
    • Minor change to correct a problem
  • Release
    • Significant program change
  • Version
    • Major program change

Principles of Information Systems, Ninth Edition

the request for maintenance form
The Request for Maintenance Form
  • Form authorizing modification of programs
  • Usually signed by a business manager
  • IS group:
    • Reviews form
    • Identifies programs to be changed
    • Determines programmer to be assigned to task
    • Estimates expected completion date
    • Develops a technical description of change

Principles of Information Systems, Ninth Edition

performing maintenance
Performing Maintenance
  • Maintenance team
    • Responsible for modifying, fixing, and updating existing software
  • Maintenance function
    • Becoming more automated

Principles of Information Systems, Ninth Edition

the relationship between maintenance and design
The Relationship Between Maintenance and Design
  • Programs are expensive to develop, but they are even more expensive to maintain
  • Determining factor in decision to replace a system
    • The point at which it is costing more to fix than to replace

Principles of Information Systems, Ninth Edition

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The Relationship Between Maintenance and Design (continued)

Principles of Information Systems, Ninth Edition

systems review
Systems Review
  • Final step of systems development
  • Analyzes systems to make sure that they are operating as intended

Principles of Information Systems, Ninth Edition

types of review procedures
Types of Review Procedures
  • Event-driven review
    • Triggered by a problem or opportunity
  • Time-driven review
    • Performed after a specified amount of time

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Types of Review Procedures (continued)

Principles of Information Systems, Ninth Edition

system performance measurement
System Performance Measurement
  • Monitoring the system
    • Number of errors encountered
    • Amount of memory required
    • Amount of processing or CPU time needed
    • Other problems
  • System performance products
    • Software that measures all components of the computer-based information system

Principles of Information Systems, Ninth Edition

summary
Summary
  • Systems development team
    • Stakeholders, users, managers, systems development specialists, and various support personnel
  • Five phases of the traditional SDLC:
    • Investigation, analysis, design, implementation, and maintenance and review
  • Advantages of the traditional SDLC:
    • Provides for maximum management control
    • Creates considerable system documentation
    • Produces many intermediate products for review

Principles of Information Systems, Ninth Edition

summary continued
Summary (continued)
  • Rapid application development (RAD)
    • Reduces paper-based documentation
    • Automates program source code generation
    • Facilitates user participation in development activities
  • Factors that affect systems development success:
    • Degree of change introduced by the project
    • Continuous improvement and reengineering
    • Use of quality programs and standards

Principles of Information Systems, Ninth Edition

summary continued1
Summary (continued)
  • Participants in systems investigation:
    • Stakeholders, users, managers, employees, analysts, and programmers
  • Data collection methods:
    • Observation, interviews, questionnaires, and statistical sampling
  • Requirements analysis
    • Determines the needs of users, stakeholders, and the organization in general

Principles of Information Systems, Ninth Edition

summary1
Summary
  • Purpose of systems design:
    • To prepare detailed design needs for a new system
  • Logical and physical design
    • Can be accomplished using the traditional systems development life cycle or the object oriented approach
  • Disaster recovery
    • Important aspect of systems design

Principles of Information Systems, Ninth Edition

summary continued2
Summary (continued)
  • Purpose of systems implementation:
    • To install the system and make everything, including users, ready for its operation
  • Software can be purchased from vendors or developed in-house
  • Cross-platform development and integrated development environments (IDEs)
    • Make software development easier and more thorough

Principles of Information Systems, Ninth Edition

summary continued3
Summary (continued)
  • Systems operation
    • Use of a new or modified system
  • Maintenance
    • Can be as simple as a program patch to the more complex upgrading of software with a new release from a vendor
  • Systems review
    • Process of analyzing and monitoring systems to make sure that they are operating as intended

Principles of Information Systems, Ninth Edition