4. Stages of the system development cycle Statement of the problem Type of new system New system Using new system Problem with system Change in purpose Change type of system Change system Change use of system Understanding the problem Making decisions Designing solutions Implementing Testing, Evaluating & maintaining
5. Stages of the system development cycle Statement of the problem Type of new system New system Using new system Problem with system Change in purpose Change type of system Change system Change use of system Understanding the problem- identifying the requirements of a system that would solve the problem. Understanding the problem Making decisions Designing solutions Implementing Testing, Evaluating & maintaining
6. Stages of the system development cycle Statement of the problem Type of new system New system Using new system Problem with system Change in purpose Change type of system Change system Change use of system Making decisions-determining the feasibility of a new system to solve the problem. Understanding the problem Making decisions Designing solutions Implementing Testing, Evaluating & maintaining
7. Stages of the system development cycle Statement of the problem Type of new system New system Using new system Problem with system Change in purpose Change type of system Change system Change use of system Designing solutions-creating the new system. Understanding the problem Making decisions Designing solutions Implementing Testing, Evaluating & maintaining
8. Stages of the system development cycle Statement of the problem Type of new system New system Using new system Problem with system Change in purpose Change type of system Change system Change use of system Implementing-using the system to solve the problem. Understanding the problem Making decisions Designing solutions Implementing Testing, Evaluating & maintaining
9. Stages of the system development cycle Statement of the problem Type of new system New system Using new system Problem with system Change in purpose Change type of system Change system Change use of system Testing, evaluating & maintaining- the ongoing operation of the system Understanding the problem Making decisions Designing solutions Implementing Testing, Evaluating & maintaining
10. Introduction The system development is important as it results in an efficient & error free as possible system. It may be important or necessary to revisit previous steps to modify or fine tune the new system.
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21. Understanding the problem It provides a quick method of determining if a project is on schedule. The chart can be used to gauge progress and to identify any problems. A Gantt chart is a popular way of managing a project Understanding the problem Making decisions Designing solutions Implementing Testing, evaluating and maintaining Time (weeks) 1 2 3 4 5 6 7
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23. Making decision Decisions are made on possible solutions that have been developed using the requirement report and the scope of the problem. Constraints are taken into consideration (Economic; Technical; Schedule & Organisational.) A feasibility study is carried out with the constraints and recommendations are made. (no change; new system; investigate another solution)
24. Making decision The management will then select the most appropriate option & the project plan may need further modification. The details of the new system are presented, along with recommendations for design, implementation and maintenance.
25. Making decision Data dictionaries contain a comprehensive description of each field in the database. They commonly include a field name, data type, number of characters (field width) & description for the purpose of the field. Context diagrams are used to represent entire information systems. The system is shown as a single process along with the inputs & outputs (external entities ) to the system.
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27. Making decision Data flow diagrams only show movement of data & not the movement of other things such as products. They do not explain how the processes works. A Decision tree is a diagrammatic way of representing all possible combinations of decisions & there resulting actions. Example here page 71 It represents the decisions made within a system as the branches of a tree. Each branch finishes in a particular action.
28. Making decision A decision table represents all possible conditions & the actions that will result. The table is divided vertically into conditions & actions & horizontally into the rules that are based on combinations of the conditions. Story boards are a diagrammatic way of representing the elements of the information system. There are two types linear (ordered) and non-linear (no order).
29. Designing Solutions Designing a solution is the transformation of the Specifications into appropriate hardware, software & information systems. It involves purchasing hardware, writing or buying software and specifying information processes to make the system operational The new system is developed from the prototype . Screen designs for input & output are created. The format & layout of each screen, report & menu must be created using good design principles.
30. Designing Solutions The technical specifications of hardware need to be identified before the hardware is bought & installed. The new system must be tested before implementation. Test data is prepared to test any potential problem. Design tools are used to better understand the system & document the new system. The tools are used to assist in explaining the operation of the new system.
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32. Implementation During the implementation stage the hardware & software is installed & tested. Participants are trained so that they understand the benefits of the new system & how to use it. Participants need to be instructed about & assisted with the major features & functions of the system over a period of time. Information processes are continually tested during the implementation of the system over a period of time.
33. Implementation Minor changes to procedures are immediately implemented. Data is converted to the new system using one of the conversion methods. The method of conversion chosen must be justified, as there are advantages & disadvantages in each of the methods.
34. Implementation Direct conversion involves the immediate change to the new system on a chosen date. (probably best for small systems) Phased conversion is the replacement of one system by another in a series of stages. (each module is tested individually & staff develops confidence in the new system.) Parallel conversion involves the old & new system both working together at the same time. ( this allows the participants & users to get used to the new system & to check the new system’s output.)
35. Implementation Pilot conversion involves building & testing the new system before replacing the old system. (the old system is still available if the new system fails or experiences problems)
36. Testing Testing is a way to verify the quality of the project. Testing a system is a very important part of the implementation of a system. Without rigorous testing, the system cannot guarantee to work as expected. Tests must be designed to examine the systems operation under all possible events.
37. Testing Testing of hardware involves use of diagnostic software. Backup systems should be tested by selecting files to be stored. Software is tested using data that has been structured to test all decisions made within the system. Test data must cover all possible combinations of data that may be encountered.
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40. STAGEPROCESSES source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Understanding the problem The first stage of the process, understanding the purpose and identifying changes that may be made to an existing system. Identify and communicate with participants in the current system. Suggest the use of a prototype to clarify participants understanding.
41. STAGEPROCESSES source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Planning The second stage involves the conducting of a feasibility study. The nature of the problem is clearly described in a report and recommendations are made to management as to whether the proposed solution is practicable. A project plan is developed.
42. STAGEPROCESSES source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Designing This third stage involves the documentation of the development of a solution to the new system. A prototype may be used to help clarify the solution to the participant. System design tools can also be used to explain the solution, for example; context diagrams, data flow diagrams, decision trees, decision tables, data dictionaries, storyboards.
43. STAGEPROCESSES source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Implementing At this stage decisions are made on how the new system will be implemented. An implementation plan is developed setting out clearly: -support for the participants of the new system through training?, -methods of testing the new system -the conversion from the old system to the new designed system. -steps in an operation manual/s.
44. STAGEPROCESSES source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Testing, evaluating and maintaining This stage is the most important; users begin to use the new system, the performance of which is tested against the design specifications. The maintenance of the new system is important through the training of participants and the reviewing of the operation manual/s.
45. STAGEPROCESSES source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Testing, evaluating and maintaining This stage is the most important; users begin to use the new system, the performance of which is tested against the design specifications. The maintenance of the new system is important through the training of participants and the reviewing of the operation manual/s.
46. STAGEPROCESSES source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Testing, evaluating and maintaining This stage is the most important; users begin to use the new system, the performance of which is tested against the design specifications. The maintenance of the new system is important through the training of participants and the reviewing of the operation manual/s.
47. STAGEPROCESSES source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Testing, evaluating and maintaining This stage is the most important; users begin to use the new system, the performance of which is tested against the design specifications. The maintenance of the new system is important through the training of participants and the reviewing of the operation manual/s.
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49. Social & Ethical issues source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm These days information systems are affecting everyone's lives. People's privacy is being compromised. People find that have been put out of work by a computer. Some people just struggle with the technology. A new system should help process the work better and a positive change. But what about the negatives? How is the system affecting the participants? Is their work load less or has it increased? Is the new system infringing on their privacy?
50. Social & Ethical issues source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Machine Centred Systems: are designed around the computer at the expense of people. The machine centred system will simplify and make the computer more efficient and the people need to work around the computer. Human Centred Systems: are designed around the needs of people first and the computers are made to fit in with the needs of the participants.
51. Social & Ethical issues source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm The Work Environment  A new system may mean drastic changes in the work environment. This may cause stress for some workers. However some changes may also be detrimental to the physical health of the participants. As such all ergonomic factors need to be taken into account when designing new systems.
52. Social & Ethical issues source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm The Changing Nature of the Workplace  Unfortunately changes in technology are not always positive and may be impacting significantly upon the social structure of the work place. Telecommuting : More workers now are able to work from home through the internet.
53. Social & Ethical issues source http://hsc.csu.edu.au/ipt/project_work/1-2/stages.htm Social Isolation : People are gregarious animals. Gregarious means that we like meeting with other people. Unfortunately technology can isolate people as well as bring people together. This is particularly a problem in machine centred work places. Deskilling : As much as the technical skills of some workers are increasing at a fast pace other areas of the work force are particularly being deskilled as the computers take over more of their work.