Systems Analysis

Lecture 3

Business and ICTICT Systems & Business Systems

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Lecture Objectives

• Recap previous lectures

– ICT in Business

– Business Case, Feasibility and Scope

• System Development Methods

• Examine General Systems Theory (system components)

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Role of Systems Analyst

SystemsAnalysis

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Business and ICT

• Impact of ICT on Business

• Impact of the Internet on Business

• B2B, B2C, C2C

• Business Process Modelling

• Factors that trigger / influence IS Projects

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ICT Projects

• Importance of:

– Business Case

– Feasibility Study & Risk Management

– Mission Statement of Business

– Vision Statement of Project

• Project Initiation Document

• Project Management5BTEC HNC Systems Support Castle College 2007/8

Development Decisions • SWOT Analysis

• In-house development

• Software packages

• Outsourcing

• Sub-contracting

• Internet-based application services

• Custom Solutions

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Combination

System Development Methods

• Structured Analysis

– Traditional method

– Process Centred Technique

• Object-Oriented Analysis (OO)

– Combines Data and Processes into Objects

– Class, Properties, Methods, Messages

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Successful Systems Development Requires:

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End Result

Development Method

Development Model

Project Management Tools

Systems Development Modelling

• Business Model• Requirements Model• Data Model• Object Model• Network Model• Process Model

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What is a system?

“An information system is a collection of interrelated components that collect, process, store and provide as output the information needed to complete a business task.”

(Satzinger, 2004)

Note: May or may not be IT based

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Information SystemsInformation systems operate in terms of:

– Goals (the desired long/medium term outcomes)

– Elements (the required hardware & software)

– Inputs (the type and quantity of data)

– Outputs (the result of the processing operations)

System Categories

We can divide systems into categories:

1. Decision support systems / Executive Information systems (top managers)

2. Office systems, (Admin) (Middle Managers and knowledge workers)

3. Operations systems (Transaction processing)

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System Components

(Model)All Systems include:

System

Inputs Outputs

Environment

Environment

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Control in Systems

• Systems function within Boundaries

• Systems need Controls

• Control Flows and ways to monitor control flows (feedback and feed-forward flows)

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Environment

Control in Systems

Inputs Outputs

Process

Control

SystemBoundary

Feed-forward

Feed-back

Control flows

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Systems and Sub-Systems

The more sub systems within the general boundary, the more complex the system becomes

sub-system

sub-systemsub-system

sub-systemsub-system

System

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Information Technology Systems• A system is a set of components that

produce a specific result *• A mission-critical system is one that

is vital to the company’s operations• Data consists of the basic facts that

are the system’s raw materials• Information is data that has been

transformed into output that is valuable to users

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Information System Components

IS contain all these components:• Hardware• Software• Data ( Information)• Processes• People

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Hardware

• Everything that is in the physical layer of information systems

• Wide array of technology choices

• Moore’s Law (1965) - computer processing power would double every 18 to 24 months

• IT systems require power and speed – multiple servers often used

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Software

• “Software refers to programs that control the hardware and produce the desired information or results”(Shelley et al p.6)

• System Software, Application Software, Enterprise Applications, Horizontal Systems, Vertical Systems, Legacy Systems.

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Data

• The raw material that an information system transforms into useful information

• Tables

• Linking

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Processes

• Processes describe the tasks and business functions that users, IT managers and IT staff members perform to achieve specific results

• Processes are the building blocks of an Information system because they represent day to day business operations

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Users

• Sometimes called End Users• People who interact with the

Information System (inside / outside)• Users depend on skilled professionals

(systems analysts, programmers, network administrators etc)

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The primary purpose of an Information system is to provide valuable information to Users

In Conclusion• System development methods and

requirements for success

• Introduced General System Theory

• Given brief overview of the components of Information Systems

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