Systems Analysis Lecture 3 Business and ICT ICT Systems & Business Systems 1 BTEC HNC Systems Support Castle College 2007/8

Lecture Objectives Recap previous lectures –ICT in Business –Business Case, Feasibility and Scope System Development Methods Examine General Systems Theory (system components) 2 BTEC HNC Systems Support Castle College 2007/8

Role of Systems Analyst Systems Analysis 3 BTEC HNC Systems Support Castle College 2007/8

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 4 BTEC HNC Systems Support Castle College 2007/8

ICT Projects Importance of: –Business Case –Feasibility Study & Risk Management –Mission Statement of Business –Vision Statement of Project Project Initiation Document Project Management 5 BTEC 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 6 BTEC HNC Systems Support Castle College 2007/8 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 7 BTEC HNC Systems Support Castle College 2007/8

Successful Systems Development Requires: 8 BTEC HNC Systems Support Castle College 2007/8 End Result Development Method Development Model Project Management Tools

Systems Development Modelling Business Model Requirements Model Data Model Object Model Network Model Process Model 9 BTEC HNC Systems Support Castle College 2007/8

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 10 BTEC HNC Systems Support Castle College 2007/8

Information Systems Information 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) 12 BTEC HNC Systems Support Castle College 2007/8

System Components (Model) All Systems include: System InputsOutputs Environment 13 BTEC HNC Systems Support Castle College 2007/8

Control in Systems Systems function within Boundaries Systems need Controls Control Flows and ways to monitor control flows (feedback and feed- forward flows) 14 BTEC HNC Systems Support Castle College 2007/8

Environment Control in Systems Inputs Outputs Process Control System Boundary Feed- forward Feed- back Control flows 15 BTEC HNC Systems Support Castle College 2007/8

Systems and Sub-Systems The more sub systems within the general boundary, the more complex the system becomes sub-system System 16 BTEC HNC Systems Support Castle College 2007/8

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 17 BTEC HNC Systems Support Castle College 2007/8

Information System Components IS contain all these components: Hardware Software Data (  Information) Processes People 18 BTEC HNC Systems Support Castle College 2007/8

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 19 BTEC HNC Systems Support Castle College 2007/8

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. 20 BTEC HNC Systems Support Castle College 2007/8

Data The raw material that an information system transforms into useful information Tables Linking 21 BTEC HNC Systems Support Castle College 2007/8

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 22 BTEC HNC Systems Support Castle College 2007/8

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) 23 BTEC HNC Systems Support Castle College 2007/8 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 24 BTEC HNC Systems Support Castle College 2007/8