Management Information Systems, 10e

50 

Teks penuh

(1)

Management

Information Systems,

10/e

(2)

Chapter 7

(3)

Learning Objectives

Recognize the systems approach as the

basic framework for solving problems of all

kinds.

Know how to apply the systems approach to

solving systems problems.

(4)

Learning Objectives (Cont’d)

Be familiar with the main SDLC approaches

the

traditional waterfall cycle, prototyping, rapid

application development, phased development,

and business process redesign.

Know the basics of modeling processes with data

flow diagrams and use cases.

Understand how systems development projects

are managed in a top-down fashion.

(5)

The Systems Approach

John Dewey identified three series of judgments

involved in adequately resolving a controversy:

Recognize the controversy.

Weigh alternative claims.

Form a judgment.

During the late 1960s/early 1970s, interest in

systematic problem solving strengthened.

(6)

Series of Steps

Preparation effort

prepares the problem solver

by providing a systems orientation.

Business areas, level of management, resource flows

Definition effort

consists of identifying the

problem to be solved

and then understanding it.

Solution effort

involves identifying alternative

solutions, evaluating them, selecting the one that

appears best, implementing that solution, and

(7)
(8)
(9)

Definition Effort Terminology

Problem trigger

is a signal that things are

going better or worse than planned.

Symptom

is a condition that is produced

by the problem and is usually more obvious

than the root cause of the problem.

(10)
(11)

Select the Best Solution

Analysis

a systematic evaluation of

options.

Judgment

the mental process of a single

manager.

(12)

Systems Development Life Cycle

Methodology

is a recommended way of doing

something.

Systems development life cycle (SDLC)

is an

application of the systems approach to the

development of an information system.

Traditional SDLC stages are:

Planning

Analysis

Design

(13)
(14)

Prototyping

Prototype

is a version of a potential

system that provides the developers and

future users with an idea of how the system

in its completed form will function.

Prototyping

is the process of producing a

prototype.

Best suited for small systems

reflecting the

(15)

Evolutionary Prototype

Evolutionary prototype

is continually refined

until it contains all of the functionality that users

require of the new system. The steps involved are:

Identify user needs.

Develop prototype.

Integrated application developer

Prototyping toolkit

Determine if the prototype is acceptable.

(16)
(17)

Requirements Prototype

Requirements prototype

is developed as a way

to define the functional requirements of the new

system when users are unable to articulate exactly

what they want. Begin with the Evolutionary

Prototype steps, then the next steps are:

Code the new system;

Test the new system;

Determine if the new system is acceptable;

(18)
(19)

Attraction of Prototyping

Communications between the developer and user

are improved.

The developer can do a better job of determining

the users’ needs.

The user plays a more active role in system

development.

The developers and the user spend less time and

effort developing the system.

(20)

Potential Pitfalls of Prototyping

The haste to deliver the prototype may produce

shortcuts in problem definition, alternative

evaluation, and documentation. The shortcut

produces a “quick & dirty” effort.

The user may get overly excited about the

prototype, leading to unrealistic expectations

regarding the production system.

Evolutionary prototypes may not be very efficient.

The computer-human interface provided by certain

(21)

Rapid Application Development

Rapid Application Development (RAD)

is a

term coined by James Martin. It refers to a

development life cycle intended to produce

systems quickly without sacrificing quality.

Information engineering (IE)

is the name that

Martin gives to his overall approach to system

development, which treats it as a firm-wide

activity.

Enterprise

is used to describe the entire firm.

(22)
(23)

Phased Development

Phased development is an approach for

developing information systems that consists of six

stages:

Preliminary investigation

Analysis

Design

Preliminary construction

Final construction

System test

(24)
(25)

Module Phases

System is subdivided into major modules

such as:

Report writer;

Database;

Web interface.

Number of modules varies with the system

from one to a dozen or so.

(26)

Figure 7.9 Analysis, Design, and Preliminary

(27)

Business Process Redesign

Reengineering

or

Business process redesign

(

BPR

) is the process of reworking the systems.

Systems include both those that process the firm’s data

and those that perform basic functions such as drilling

for oil.

BPR

affects the firm’s IT operations in two ways:

Aids in the redesign of old information systems (

legacy

systems);

(28)
(29)

Strategic Initiation of BPR

Reverse engineering

is the process of analyzing

an existing system to:

Identify its elements and their interrelationships;

Create documentation at a higher level of abstraction

than currently exists.

Functionality

is the job that it performs.

Reengineering

is the complete redesign of a

system with the objective of changing its

functionality.

(30)

BPR Components

BPR components can be applied separately

or in combination.

Functional quality

is a measure of what

the system does.

(31)
(32)

Methodologies in Perspective

Traditional SDLC

is an application of the

systems approach to the problem of system

development; contains all elements.

Prototyping

is an abbreviated form focusing on

the definition and satisfaction of user needs.

RAD

is an alternative approach to the design and

implementation phases of SDLC.

(33)

System Development Tools

Process modeling

was first done with

flowcharts

.

ISO standards

Use of 20+ symbols

Data flow diagrams (DFD)

is a graphic

representation of a system that uses four symbol

shapes to illustrate how data flows through

interconnected processes.

(34)

Data Flow Diagram Symbols

Terminator

describes an environmental element, such as

a person, organization, or another system.

Environmental elements

exist outside the boundary of the

system.

Process

is something than transforms input into output.

Data flow

consists of a group of logically related data

elements that travel from one point or process to another;

can

diverge

and

converge

.

Data storage

is a repository of data.

(35)
(36)

Leveled Data Flow Diagrams

Leveled DFDs

is used to describe the hierarchy of

diagrams, ranging from context to lowest-level

n

diagram.

Figure 0 diagram

identifies the major processes of a

system.

Use additional DFDs to achieve documentation at both a more

summarized and a more detailed level.

Context diagram

is a diagram that documents the

system at a more summarized level.

Positions the system in an environmental context.

Figure

n

diagram

is a diagram that provides more detail.

(37)
(38)
(39)

Use Cases

Use case

is a narrative description in an outline

form of the dialog that occurs between a primary

and secondary system.

Continuous narrative format

with each action

numbered sequentially.

Ping-pong format

consists of two narratives and

the numbering indicates how the tasks alternate

between the primary and secondary systems.

Alternative events are actions that are not

(40)
(41)
(42)

Project Management

Steering committee

is a committee with the

purpose of providing ongoing guidance, direction,

and control of all systems projects.

MIS steering committee

purpose is directing

the use of the firm’s computing resources.

It establishes policies.

It provides fiscal control.

(43)
(44)

Project Leadership

Project team

includes all of the persons

who participate in the development of an

information system.

(45)

Project Management Mechanism

Basis for project management is the project plan.

Gantt chart

is a horizontal bar chart that includes

a bar for each task to be performed; bars

arranged in time sequence.

Network diagram

(

CPM diagram, PERT

chart

) is a drawing that identifies activities and

links them with arrows to show the sequence in

which they are to be performed.

Narrative reports are in the form of weekly written

(46)
(47)
(48)

Project Cost Estimating

Cost-estimating inputs

Work breakdown structure (WBS)

Resource requirements, resource rates

Activity duration estimates

Historical information

Cost-estimating tools and techniques

Bottom-up estimating

Computerized tools

Mathematical models

Cost-estimating outputs

(49)
(50)

Figur

Figure 7.1 Phases and Steps of Systems Approach
Figure 7 1 Phases and Steps of Systems Approach . View in document p.7
Figure 7.2 Each Business Area Is a System
Figure 7 2 Each Business Area Is a System . View in document p.8
Figure 7.3 Each Part of the System Is Analyzed in Sequence
Figure 7 3 Each Part of the System Is Analyzed in Sequence . View in document p.10
Figure 7.4 The Circular Pattern of the System Life Cycle
Figure 7 4 The Circular Pattern of the System Life Cycle . View in document p.13
Figure 7.5 Development of an Evolutionary Prototype
Figure 7 5 Development of an Evolutionary Prototype . View in document p.16
Figure 7.6 Development of a Requirements Prototype
Figure 7 6 Development of a Requirements Prototype . View in document p.18
Figure 7.7 Rapid Application Development Is an Integral Part of Information Engineering
Figure 7 7 Rapid Application Development Is an Integral Part of Information Engineering . View in document p.22
Figure 7.8 The Stages of the Phased Development Methodology
Figure 7 8 The Stages of the Phased Development Methodology . View in document p.24
Figure 7.9 Analysis, Design, and Preliminary Construction are Performed on Each System Module
Figure 7 9 Analysis Design and Preliminary Construction are Performed on Each System Module . View in document p.26
Figure 7.10 Top-Down Initiation of BPR Projects
Figure 7 10 Top Down Initiation of BPR Projects . View in document p.28
Figure 7.11 BPR Component Selection Is Based on Both Functional and Technical Quality
Figure 7 11 BPR Component Selection Is Based on Both Functional and Technical Quality . View in document p.31
Figure 7.12 A DFD of a Sales Commission System
Figure 7 12 A DFD of a Sales Commission System . View in document p.35
Figure 7.13 A Context Diagram of a Sales Commission System
Figure 7 13 A Context Diagram of a Sales Commission System . View in document p.37
Figure 7.14 A Figure 4 Diagram of a Sales Commission System
Figure 7 14 A Figure 4 Diagram of a Sales Commission System . View in document p.38
Figure 7.15 A Use Case
Figure 7 15 A Use Case . View in document p.40
Figure 7.16 Use Case Guidelines
Figure 7 16 Use Case Guidelines . View in document p.41
Figure 7.17 Managers of a System Life Cycle Arranged in a Hierarchy
Figure 7 17 Managers of a System Life Cycle Arranged in a Hierarchy . View in document p.43
Figure 7.18 A Gantt Chart
Figure 7 18 A Gantt Chart . View in document p.46
Figure 7.19 A Network Diagram
Figure 7 19 A Network Diagram . View in document p.47
Table 7.1 Components of Cost-Estimating Process
Table 7 1 Components of Cost Estimating Process . View in document p.49

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