Title: Fundamentals of Information Systems Fourth Edition
1Fundamentals of Information SystemsFourth Edition
- Chapter 8
- Systems Development
Includes Some content from AK ITEC 2010 F 2006
2Principles and Learning Objectives
- Page 339
- Review Principles as an overview of chapter.
- Pay attention to acronyms !
LEARN THE SDLC You will need it for the rest
of your life AND it WILL be on the exam !!!
3Why Learn About Systems Development?
- Important to learn how to
- Initiate systems development process
- Analyze your needs with help of IS personnel
- Learn how a project can be
- Planned
- Aligned with corporate goals
- Rapidly developed
See page 340
4Participants in Systems Development
- Development team consists of the following
- Project managers coordinate system development
effort - Stakeholders directly or indirectly benefit from
the project - Users interact with the system regularly
- Systems analysts analyze and design business
systems - Programmers modify or develop programs to
satisfy user requirements - Various support personnel specialists, vendors
P 341
5Information 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 is
critical for any successful systems development
effort - Determining whether organizational and IS goals
are aligned can be difficult
6Information Systems Planning and Aligning
Corporate and IS Goals (continued)
Figure 8.2 Information Systems Planning
7Systems Development Life Cycles
- The systems development process is also called a
systems development life cycle (SDLC) - Common SDLCs
- Traditional systems development life cycle
- Prototyping
- Rapid application development (RAD)
- End-user development
This classification is inconsistent with that
used for ITEC 2010.
8The Traditional Systems Development Life Cycle
LEARN !!
Figure 8.3 The Traditional Systems Development
Life Cycle
9The Traditional Systems Development Life Cycle
(continued)
- Systems investigation problems and opportunities
are identified and considered in light of the
goals of the business - Systems analysis study of existing systems and
work processes to identify strengths, weaknesses,
and opportunities for improvement - Systems design answers the question How will
the information system do what it must do to
obtain the problem solution?
10The Traditional Systems Development Life Cycle
(continued)
- Systems implementation creation or acquisition
of various system components detailed in the
systems design, assembling them, and placing the
new or modified system into operation - Systems maintenance and review ensures the
system operates as intended and modifies the
system so that it continues to meet changing
business needs
11Prototyping
- An iterative approach to systems development
Some other references consider prototyping as
part of different phases (analysis,
implementation) of the SDLC.
Figure 8.4 Prototyping
12Rapid Application Development, Agile Development,
Joint Application Development, and Other Systems
Development Approaches
- Rapid application development (RAD)
- Systems development approach that employs tools,
techniques, and methodologies designed to speed
application development - Some iterative development approaches allow the
system to change as it is being developed - Agile development frequent face-to-face meetings
between systems developers and users - XP programming pairs of programmers work
together to develop robust systems quickly
13Rapid Application Development, Agile Development,
Joint Application Development, and Other Systems
Development Approaches (continued)
- Pages 346 347 Read carefully three times.
Learn RAD JAD acronyms. - Study Extreme Programming, GSSs.
14The End-User Systems Development Life Cycle
- End-user systems development any systems
development project in which the primary effort
is undertaken by a combination of business
managers and users - End-user-developed systems can be structured as
complementary to, rather than in conflict with,
existing and emerging information systems
15Outsourcing and On Demand Computing
- An outside consulting firm or computer company
that specializes in systems development can take
over some or all of the development and
operations activities - Reasons for using outsourcing and on demand
computing - Reducing costs, obtaining state-of-the-art
technology, eliminating staffing and personnel
problems, and increasing technological
flexibility
16Use of Computer-Aided Software Engineering (CASE)
Tools
- Computer-aided software engineering (CASE) tools
that automate many of the tasks required in a
systems development effort and encourage
adherence to the SDLC - Instill a high degree of rigor and
standardization to the entire systems development
process - Upper-CASE tools focus on investigation,
analysis, and design - Lower-CASE tools focus on implementation
17Object-Oriented Systems Development
- Object-oriented systems development (OOSD)
approach to systems development that combines the
logic of the systems development life cycle with
the power of object-oriented modeling and
programming
18Systems 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?
P 350
19Initiating Systems Investigation
- Systems request form document filled out by
someone who wants the IS department to initiate
systems investigation - Helps rationalize and prioritize the activities
of the IS department - Includes the following information
- Problems in and opportunities for system
- Objectives in investigation
- Overview, costs, and benefits of proposed system
20Feasibility Analysis
- Technical feasibility hardware, software, and
other system components - Economic feasibility predicted benefits vs. cost
and time - Legal feasibility limitations of laws and
regulations on project - Operational feasibility logistical and
motivational considerations - Schedule feasibility completion of project in
reasonable amount of time
21Object-Oriented Systems Investigation
- Key objects can be identified during systems
investigation - Use case diagram
- Part of the Unified Modeling Language (UML) used
in object-oriented systems development - Actors represent persons interacting with system
- Use cases represent system activity in response
to an event.
See Sys Anal des pg 221.
22Object-Oriented Systems Investigation (continued)
Figure 8.8 Use Case Diagram for a Kayak Rental
Application
23The Systems Investigation Report
- Systems investigation report
- Summary of the results of the systems
investigation and the process of feasibility
analysis - Recommendation of a course of action
- Continue systems analysis
- Modify the project
- Abandon the project
- Reviewed by steering committee of senior
management and users
24Systems Analysis
- Answers the question What must the information
system do to solve the problem? - Overall emphasis of systems analysis is
- Gathering data on the existing system
- Determining the requirements for the new system
- Considering alternatives within these constraints
- Investigating the feasibility of the solutions
- Primary outcome prioritized list of systems
requirements
25Data Collection
- Identifying sources of data
- Internal sources
- External sources
- Collecting data
- Interviews structured and unstructured
- Direct observation
- Questionnaires structured or unstructured
- Used when data sources are spread over a wide
geographic area
26Data Analysis
- Data analysis
- Manipulation of collected data so that systems
development team can use the data - Data modeling
- Entity-relationship (ER) diagrams objects,
attributes, and associations - Activity modeling
- Data-flow diagrams (DFDs) objects, associations,
and activities
27Data Analysis (continued)
Figure 8.12 Data and Activity Modeling (b) A
data-flow diagram
28Data Flow Diagrams (DFDs)
- Graphical system model that shows all main
requirements for an IS in one diagram or set of
diagrams - Inputs/outputs,
- Processes,
- Data storage.
- Easy to read and understand with minimal
training. Ref San Diego Periodicals.
Slide from ITEC 2010
29Data Flow Diagram Symbols(Figure 6-3)
Learn !
Slide from ITEC 2010
30Data Analysis (continued)
Figure 8.12 Data and Activity Modeling (a) An
entity-relationship diagram
31Data Analysis (continued)
Figure 8.12 Data and Activity Modeling (c) A
semantic description of the business process
32Customers, Orders, and Order Items
Slide from ITEC 2010
33ERD with Many-to-Many Relationships
Slide from ITEC 2010
34Many-to-Many Relationship Converted to
Associative Entity to Store Grade Attribute
Slide from ITEC 2010
35Requirements Analysis
- Determines user, stakeholder, and organizational
needs through the following techniques - Asking directly best for stable systems
- Critical success factors asks for critical
factors in interviewees area - IS plan translates strategic plan into
initiatives - Requirements analysis tools CASE tools
36Requirements Analysis (continued)
Figure 8.13 Converting Organizational Goals into
Systems Requirements
37Object-Oriented Systems Analysis
- Identifying problems or potential opportunities
- Identifying key participants and collecting data
- Uses classes and generalization/specialization
hierarchies instead of data-flow diagrams and
flowcharts
Be able to recognize a class diagram box.
38Object-Oriented Systems Analysis (continued)
Figure 8.14 Generalization/Specialization
Hierarchy Diagram for Single and Tandem Kayak
Classes
39The Systems Analysis Report
- Systems analysis report should cover
- Strengths and weaknesses of the existing system
from a stakeholders perspective - User/stakeholder requirements for the new system
(also called the functional requirements) - Organizational requirements for the new system
- Description of what the new information system
should do to solve the problem
40Systems Design
- Answers the question How will the information
system solve a problem? - Has two dimensions logical and physical
- Logical design description of the functional
requirements of a system - Physical design specification of the
characteristics of the system components
necessary to put the logical design into action
41Object-Oriented Design
- Design key objects and classes of objects in the
new or updated system - Consideration of the problem domain, the
operating environment, and the user interface - Consideration of the sequence of events that must
happen for the system to function correctly - Scenario sequence of events
- Can be diagrammed in a sequence diagram
42Object-Oriented Design (continued)
Figure 8.16 A Sequence Diagram to Add a New
KayakItem Scenario
43Generating Systems Design Alternatives
- Request for proposal (RFP) document that
specifies in detail required resources such as
hardware and software - Financial options
- Purchasing
- Leasing
- Renting
44Systems Implementation
Page 364
Figure 8.19 Typical Steps in Systems
Implementation
45Acquiring Hardware from an IS Vendor
- IS vendor company that offers hardware,
software, telecommunications systems, databases,
IS personnel, and/or other computer-related
resources - Buying computer hardware
- Leasing computer hardware
- Renting computer hardware
- Pay-as-you-go, on-demand, or utility
computing
46Data Preparation
- Also called data conversion
- Ensures all files and databases are ready to be
used with new computer software and systems
47Testing
- Unit testing testing of individual programs
- System testing testing the entire system of
programs - Volume testing testing the application with a
large amount of data - Integration testing testing all related systems
together - Acceptance testing conducting any tests required
by the user
48Start-Up
- Process of making the final tested information
system fully operational - Approaches
- Direct conversion (plunge, direct cutover)
stopping the old system and starting the new one
on a given date - Phase-in approach (piecemeal) slowly replacing
old system components with new system components - Pilot start-up run new system with one group of
users - Parallel start-up running old and new systems
together for a period of time
49User Acceptance
- User acceptance document formal agreement signed
by the user that states that a phase of the
installation or the complete system is approved - Legal document that removes or reduces IS
vendors liability
50Systems Review
- Process of analyzing systems to make sure that
they are operating as intended - Often compares the performance and benefits of
the system as it was designed with the actual
performance and benefits of the system in
operation - Event-driven review triggered by a problem or
opportunity such as an error, a corporate merger,
or a new market for products - Time-driven review performed after a specified
amount of time