Types of Systems; CASE tools

Class 3

Why study SA&D? “meat” of the IS function Winchester house example Art vs. Science

Methodologies Comprehensive, multiple-step approaches to systems

development Models

Representation of system, organization, etc. Techniques

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 limited-time 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

Used to track geographic information Communication Support Systems

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 versusProcess Oriented

Data Oriented Process Oriented

Focus Data the system needs to operate

What system is supposed to do and how

Organization

Data files designed for 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

Tools that enable automatic checking for incomplete, inconsistent, or incorrect specifications in diagrams, forms, and reports

Central repository / Data dictionary Repository of all data definitions for all

organizational applications Documentation generators Code generators