Chapter 1: Introduction to Systems Development Systems concepts The information systems infrastructure Top-down information systems development Methodologies and tools Keys to success as a systems developer The Functions/Components Matrix

Systems Concepts Physical and conceptual Open and closed Fig 1.1: An Open System

Systems Concepts Open-loop and closed-loop The firm as a transformation system Fig 1.2: A Closed-loop System

Systems Concepts System levels Supersystem, suprasystem System Subsystem

Systems Concepts The Control Mechanism Management Information professor Standards

Fig 1.7: Standards Information Flows to the Information Processor Systems Concepts

Fig 1.8: Decision Information Flows to the Physical System Systems Concepts

Fig 1.9: Information Flows to Management Systems Concepts The Feedback Loop

Systems Concepts Add some environmental flows and you have the general systems model of the firm The manager uses the model. The systems developer uses the model. Systems developers: Information specialists and users working together

Fig 1.10: The General Systems Model of the Firm Systems Concepts

The Information Systems Infrastructure Accounting Information System (AIS) Management Information System (MIS) Decision Support Systems (DSS) Office Automation Systems Expert Systems

Fig 1.11: A System Structure The Information Systems Infrastructure

Top-down Information Systems Development Fig 1.12: Systems Development Planning Framework

Methodologies Traditional system development life cycle (SDLC) Prototyping Phased development Fig 1.14: Phased Development Methodology

Tools Data modeling (ERDs, data dictionary) Process modeling (DFDs, structured English) Object modeling (class, structure, statechart diagrams, etc.)

Keys to Success as a System Developer Fig 1.16: A Project Team

Keys to Success as a System Developer Fig 1.15: The Communication Chain

Keys to Success as a System Developer Knowledge Computer literacy Business fundamentals Systems theory Information use in problem solving The systems development process Systems modeling

Keys to Success as a System Developer Skills Communications Analytical ability Creativity Leadership

Functions/Components Matrix Information system components (resources) People (information specialists, users) Data Information Software Hardware Information system functions Input Processing Output Storage Control

Fig 1.17 A Functions/Components Matrix with Selected Entries Functions/Components Matrix