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SYSTEM DEVELOPMENT -Understanding the Problem IPT- 2009 Miss O’Grady.

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Presentation on theme: "SYSTEM DEVELOPMENT -Understanding the Problem IPT- 2009 Miss O’Grady."— Presentation transcript:

1 SYSTEM DEVELOPMENT -Understanding the Problem IPT- 2009 Miss O’Grady

2 WHY ARE NEW INFORMATION SYSTEMS DEVELOPED? Either an existing system no longer meets the needs of its users or new needs are identified that could be met by an information system.

3 System Development Life Cycle 1.Understanding the Problem 2.Planning 3.Designing 4.Implementing 5.Testing, Evaluating and Maintaining

4 Refer to Page 24 of Textbook- IPT Samuel Davis Complete Group Task with a partner (5-10mins)

5 Complete Group Tasks on pg 25 in your textbook

6 UNDERSTANDING THE PROBLEM

7 Understanding the Problem The primary aim of this first stage of the SDLC is to determine the purpose and requirements of a new system. System Analyst System Analyst A person who analyses systems, determines requirements and designs new information systems.

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9 Requirements Report The purpose of the system An analysis of the existing system Definition of the Requirements

10 What needs to be done? Interview/Survey Users of the Existing System Interview/Survey Participants in the Existing System Requirements Prototypes Define the Requirements for a New System

11 Interview/Survey Users of the Existing System The users being the people who utilise the information created by the system. Example : Customers The results of surveys are often more useful for highlighting existing problems rather than revealing new needs and ideas that are not currently being addressed. New needs & ideas are more likely to reveal themselves through interviews.

12 Complete Group Task on page 28 which asks you to have a look at the survey on page 29.

13 Interview/Survey Participants of the Existing System Participants will have an understanding of the part of the system they primarily interact. They are able to identify problems and often have ideas in regard to solving these problems. System analysts often perform analysis with participants. Writes down each step performed to complete a task, time as well as inputs and outputs.

14 Complete Group Task on page 31

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17 Complete Group Task on page 33- ‘List the tasks performed by Fred during his work with Pet Buddies so far. Identify the skills Fred possesses to complete these tasks’.

18 Explaining the sequence of activities to Iris and Tom. Create customer satisfaction survey. Organise and analyse results of the survey. Telephoning a sample of customers. Develop a list of user needs and requirements. Task analysis of Tom and Iris. Various ongoing discussions with Iris and Tom. Creation of context diagrams and DFDs of existing system. Delivering presentation and question/answer session with experts.

19 Requirements Prototypes A working model of an information system, built in order to understand the requirements of the system. Screen Generators Reporting Generators

20 Requirement Report Outline Refer to page 38-39

21 Pet Buddies Requirements Report Introduction Part 1

22 CONTEXT DIAGRAMS - Shows the data that enters and leaves an information system.

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24 DATA FLOW DIAGRAMS - Shows how data moves through a system.

25 External Entity Process Data Store Data Flow

26 EXERCISE  Textbook- Page 43,44 & 45  Read page 43 & 44 and complete questions on page 45 on a piece of paper with your name at the top and hand in for marking.

27 Testing Evaluating and Maintaining By Melad, Andrew, Brenton, Michael, Matthew

28 Testing to Ensure system meets requirements Tests involve: Volume Data Simulated Data Live data

29 Volume Data tests a system with large amounts of data it ensures the system will function under large data loads TDG (test data generator) reads definition of data base and makes up data

30 Simulated Data For testing the system under simulated conditions For testing system performance under different scenarios Software is used to make the simulated data One example is mercury interactive load runner

31 Live Data it tests the system using actual data the fully operational system would use it ensures a system operates in real situations it begins straight after implementation

32 Trialing and using the operational manual the operation manual describes procedures participants must follow when using the new system there’s a trial period and usually results to modifications to the manual there usually step by step instructions operational manuals are constantly upgraded

33 Ongoing evaluation to monitor performance` Technical performance monitoring Aims to evaluate the continuing achievement of the systems evolving requirements Some old requirements may go down in priority. Other new requirements will emerge and existing ones will change. Ongoing evaluation aims to verify that all requirements continue to be met and identify any changes

34 Financial performance monitoring Includes analyzing the system’s economic feasibility. Largely about evaluating the accuracy of the economic predictions made in the feasibility study. Aim is to evaluate the extent which the new system achieving its economic goals Ongoing evaluation to review the effect on users, participants and people within the environment Surveys the effectiveness of the new system

35 Decreased privacy including perception of decreased privacy Privacy act 1988- Info system containing personal info must legally explain: Explain why personal info is collected Provide individuals with access to their records Correct inaccurate info Describe to individuals the purpose of holding info Describe info held and how its managed Changes in the type and nature of employment New system will alter work performance by people. Positive or negative effects

36 Health and safety concerns Workers exposed to health and safety problems Employers responsible to minimise risks and set up procedure for identifying and take course of action on OHS issues Makes sure the environment is ergonomic. Furniture, lighting, noise level, airing/ circulation etc. Little or no sense of accomplishment Workers need a sense of accomplishment Tasks must have purpose, a start and end point. Variety needed to min. boredom Deskilling Info system performs processes were once performed by participants May result in job loss or retrain to use new software Loss of social contact Becoming a common issue Working at home is less social as well as working long hours

37 Maintaining the system to ensure it continues to meet requirements Systems need this to ensure it keeps meeting requirements. Involves Regular maintenance & repairs when faults occur Some tasks include: Maintaining a hardware and software inventory Perform backups of they systems data and ensure they are in a safe location Protect against viruses by ensuring virus software is used and updated Ensure illegal software is not installed and all software is licensed Maintain hardware Install replacement hardware and software Setup network access Monitoring uses of peripheral devices Purchasing and replacing faulty hardware Ensure new users receive training

38 Modifying parts of the system where problems are identified Problems identified during any of the tasks require modifications to the system New requirements will emerge over the life of the system that will require modifications to be made For each new modification the SDLC commences again Necessary to ensure modification works correctly with all parts of the system and ensure all documentation is updated.


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