Introduction to Information System Development

 IS that uses computer and communication technology to perform tasks  Basic component:  Hardware  Software  Database  Telecommunication  Procedures  People

 Physical component of computer system  System unit and motherboard are used to support and tie other components together  Consists of:  Input device ▪ Capture and translate data into a form that can be processed and used by other parts of computer ▪ Eg: keyboard, pointing device, bar code scanner

 Computer is composed of the CPU and internal memory ▪ CPU is the chip that performs the instructions received from software ▪ Internal memory/Random Access Memory is a temporary memory that hold software instruction and information for CPU ▪ To permanently store info and recall them, information need to be store in secondary storage device/external memory

 Output device ▪ Provide copies of data and information on paper, video screen, etc.  Modems ▪ Input or output device that allow a computer to transfer data between each other.

 Set of instructions  Eg: computer code that hardware devices carry out to process info  Software is fundamental to computer  Database software is a software that allows you to arrange, modify and extract data from a database to create info

 Telecommunication is a vital computer based tool to help communicate information to people in other location  Computer network through the use of communication technology can share resources such as storage database and processing power  Can send and receive information through network

 Integral part of Information System  Includes management and end user  Manager use information to make decisions  End user supply data to Information System and receive info from Information System

 A series of steps undertaken in a prescribed manner to accomplish a certain job  Human activities requiring people to interact with other components of IS  Can be written in form of manual or documentation such as diagram  When procedures are embodied in computer program, they are considered part of Information Technology component

 System development lifecycle is a series of recommended steps or phases designed as guideline as to what you should do and when you should do it  Actual number of phases and the name given to each phase differs from one organisation to another  It is simplified by combining some of the phases

 The phases have a defined product or deliverable  Deliverables can be used to monitor productivity and quality of activities performed  Phases may have more than one deliverable

 SDLC use to organize activities needed to build a system  Assist management by providing reports on project status and keeping track of resource need  Consist of: 1. System planning i. Prior to developing Information System, long term and short term planning must be done to prevent poor analysis and design of new system ii. Preliminary investigation is a brief study of the problem.

iii. Output of this step is the project goal, scope and boundary and the terms of reference of the project iv. May include any restrictions such as part of existing system which cannot be changed, etc v. Also include rough idea of resource requirement of next phases vi. The objective of IS project mgt is to deliver a system that is acceptable to users and develop within time and budget vii. IS project mgt is the process of planning, scheduling and controlling the activities during the SDL

2. System analysis i. Is the detail understanding of important features of system under investigation ii. Include finding out how the existing system works, problems and the user requirement of the new system iii. Determining accurate user information needs and system requirements is important because the design of new system will be based on these determined requirement

3. System design i. Information need and system requirement in system analysis are studied in more detail ii. Can be divided into general and detail system design ▪ At the end of general system design, we will know what we need to develop and may include what software to use ▪ Detail system design/physical system design is the ext of general design. ▪ During this design, input, output, interface, database, network, programme and control are defined and documented

4. System construction and implementation i. During system construction, the individual system components are built ii. New programs and changes to existing program are written and tested iii. During implementation, the component built during construction are put into operational use iv. After the new system is completed and working, post implementation review is performed to evaluate the new system and suggest minor changes to be made

5. System maintenance i. To eliminate errors in the system ii. Implies that there is continuous improvement of the new system implemented

 Structured Development  Employs a variety of diagrams and documentations for describing the requirement of IS  Eg: DFD, ERD and structured diagram  Involve users in developing the IS  User need to participate in the analysis and design process as they are the people who use the system  Emphasis on logical system design  Major critics: takes too long and require too much documentations

 Object-Oriented Development  System developer first define the object needed in the new or revised IS  If object already exist, they are reused. If not they will select an existing object that is closed to the one needed and then modify the existing object as necessary  Unified Modeling Language (UML) is an object oriented programming language use to describe IS

 End user  People who directly interact with IS  Supply data to IS and receive info from IS  Business analyst  Analyses the business aspects and issues surrounding the IS identifying how they will provide business value in creating, developing and designing new procedure and policies together with the system analyst  Will have business exp and some type of professional training

 System analyst  Focuses in IS issue surrounding the system by identifying how IT can improve business processes, design the IS and the new business processes and ensure compliance with std  Responsible for planning, undertaking and coordinating overall dev activities  Likely to have significant training in analysis and design, programming and even areas of business

 Infrastructure analyst  Identify and implement infrastructure changes on technical issues involve in how the system will interact with the org’s infrastructure – Eg: hardware, software, database, network  Likely has significant training and exp in database administration, networking and etc

 Change management analyst  Focuses on people and mgt issues surrounding the IS installation  The roles include ensuring that adequate documentation and support is available to user, provide user training on the new system and developing strategies to overcome resistance to change  Likely have significant training and exp in organizational behavior in general and change mgt in particular

 Project manager  Oversees the system dev project from beginning to end, manages the project team, dev and monitors project plan, assign resources and act as primary point of contract for the entire systems project  Likely have exp in project mgt and likely has work for many years as system analyst