Types of Systems;
CASE tools
Class 3
Why study SA&D?



“meat” of the IS function
Winchester house example
Art vs. Science

Methodologies


Models


Representation of system, organization, etc.
Techniques


Comprehensive, multiple-step approaches to systems
development
Particular processes used when following methodology
Tools

Computer programs which aid development process
Types of Systems



Operational Control
Management Planning/Control
Strategic Planning
Transaction Processing
Systems (TPS)




Computer-based versions of manual
organization systems dedicated to handling
the organization’s transactions.
Oldest systems, bread & butter of
organizations, started in accounting
Operational level: payroll, compensation,
plant scheduling, order tracking
Outputs: detailed reports, lists, summaries
Management Information
Systems (MIS)



Computer based systems designed to provide
standard reports for managers about
transaction data.
Management level systems: annual
budgeting, capital investment analysis,
relocation analysis, inventory control, sales
region analyses
Outputs: Summary and exception reports
Executive Information Systems
(EIS)



Computer based systems developed to
support the information-intensive but limitedtime decision making of executives.
Strategic level systems: profit planning,
manpower planning, 5-year budget
forecasting, 5-year sales forecasting
Outputs: projections, responses to queries
Decision Support Systems
(DSS)




Computer-based systems designed to
help organization members make
decisions.
Management level-Strategic level:
Systems similar to MIS and ESS
Outputs: special reports, decision
analyses, responses to queries
GDSS: type of DSS to support groups
Expert Systems


Computer based systems designed to
mimic the performance of human
experts.
All levels from operational to strategic
potential.
Others

Geographic Information Systems


Communication Support Systems


Used to track geographic information
Used to facilitate communication between
customers, employees, suppliers
Office Support Systems

Used to facilitate sharing of business
documents
Data versus Process

Process-oriented approach


Focuses on how and when data are moved and
changed
Data-oriented approach

Focuses on the ideal organization of data rather
than on where and how data are used.
Data Oriented versus
Process Oriented
Focus
Data Oriented
Process Oriented
Data the system needs to
operate
What system is supposed to do
and how
Organizat Data files designed for
ion
organization
Data files designed for each
application
State of
Data
Limited duplication, limited
redundancy
Much duplication, much
redundancy
Stability
More accurate, more
enduring
Limited – more inaccuracy
Computer-Aided Software
Engineering (CASE)


Software tools that provide automated
support for some portion of the systems
development process.
Assists system builders in managing the
complexities of information system projects
and helps assure that high-quality systems
are constructed on time and within budget.
Evolution of CASE




Art vs. Science
Lack of consistency in systems
development
Predominantly used with PCs
Supports wide variety of system
development activities
CASE tools


Diagramming tools
Analysis tools


Central repository / Data dictionary



Tools that enable automatic checking for
incomplete, inconsistent, or incorrect
specifications in diagrams, forms, and reports
Repository of all data definitions for all
organizational applications
Documentation generators
Code generators