Developing Information Systems

Information Processes and Technology

Developing Information Systems

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The diagram below is known as the ............................. . A new system is generally developed when there is a belief that the changes will .............. the organisation in some way. The five stages of the System Development Cycle can be remembered using the acronym:

Traditional System Development

Approach (Waterfall Model)

Understanding the

Problem

Planning

Designing

Implementing

Testing, Evaluating and

Maintaining

Time

Understanding the problem – identifying the requirements of a system that would solve the problem. Planning – determining the feasibility of a new system to solve the problem. Deciding on a way to proceed. Designing Solutions – creating the new solution Implementing - Using the System to solve the problem Testing, evaluating and maintaining – the ongoing operation of the system.

Planning



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Stage Tasks

Understanding the problem

Determine the nature of the problem Define the purpose of the system

Planning Make decisions for a solution that takes the following into account:

Techncial Feasibility

Organisational Feasibility

Economic Feasibility

Schedule Feasibility

Desiging Solutions

Design the solution according to the decisions made above and use project management tools

Implementing solutions

Implement either:

Parallel

Phased

Pilot

Direct

Testing, evaluation and maintenance

Test before /during & after Implementation. Evaluate performance of system against specifications.



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Planning



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Understanding the Problem This stage ascertains the exact nature of the problem and whether or not the problem could be solved by an information system. This may involve redefining the problem and identifying its important elements. A clear problem statement is essential at this stage. The ............................ determines whether a new system should be implemented or whether the existing system can be altered to solve the problem. The way the system operates, including its problems need to be understood in this section. The preliminary invetsigation takes into account the needs and concerns of all the participants. Participants (users) give a real indication of the system and its flaws as they continually use the system day in day out. These views are gathered through the use of ............................ methods. These data collection methods include:

Interviews

Observation o

Questionnaires/Surveys

Measurements

A requirements report is a document that is produced in the early stages of a project that seeks to clarify the purpose of the system. This purpose is usually detailed in terms of what the users/participants needs are. The data inputs should be clearly identified. The information processes performed on the data need to be documented. Finally, the information outputs from the systems need to be detailed. The requirements report provides documentary evidence of the scope of the project. The requirement report also provides:

1. an ....................... of the new system 2. the ...................... processes of the new system 3. the ...................... required in the new system



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The project plan organises the project by specifying ....................................... . It includes Gantt charts the scheduling of tasks etc. A Gantt chart is a popular way of managing a project. It provides a quick way of determining if the project is on schedule. A Gantt chart is a bar chart with each bar representing a task. The vertical axis lists all the tasks and the horizontal axis shows the time frame.



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Planning This stage involves methodical planning using the data gathered in the preliminary investigation. The first task is to develop one or more potential solutions to the problem. A computer system should be seen only as a tool that may offer the best solution to the problem. It is not the solution to every problem. Each potential solution is developed using the requirement report and the scope of the problem. The scope of the problem places constraints on the new system. A…………………… is a factor that affects the system and may prevent it from achieving its objectives. There are different types of constraints such as financial, technical, environmental and personal. For example, a financial constraint would be the amount of money an organisation is prepared to spend on the system. After establishing several potential solutions, the systems analyst seeks approval from the management of the organisation.

Feasibility study

A feasibility study is a short report that analyses potential solutions and makes a recommendation. It does not attempt to find a detailed solution. Feasibility studies are an extension of the preliminary investigation. The result of the feasibility study is the recommendation. The recommendation is based on a number of criteria, such as economic, technical, schedule and organisational.

…………………. feasibility compares the costs of developing the new system with the expected benefits. A financial analyst is often used to assess economic feasibility. ……………feasibility is also called cost/benefit analysis.

……………feasibility determines the information technology requirements of the new system and the technical demands that will be placed on the new system.

……………feasibility determines whether time is available to implement the new system.

……………feasibility determines whether the new system will fit into the organisation and meet its current goals. It determines if the new system will have enough support to be successfully implemented.

A feasibility study can make one of three recommendations: no change, develop a new system, or investigate other solutions. The decision to proceed with a new system is made by the managers of the organisation. Analysis When the data is collected it must be organised and analysed. It is necessary to understand the flow of data through the system and how the data is processed within the system. A range of tools are used for this purpose, such as context diagrams and data flow diagrams.



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Designing Solutions When the analysis is completed, the new system is designed. Systems Analysts use a top down approach, where large, complicated problems are broken down into a series of smaller problems that are easier to solve. The tools used for design include the following:

Diagrams Definition Symbols Used

Context diagram Context diagrams are used to represent an overview of the entire information system. The system is shown as a single process along with the inputs and outputs. The external entities are connected to the single process by data flow arrows. Each element represented is labelled. A context diagram does not show data stores and internal processes

Data Flow Diagrams Data flow diagrams represent an information system as a number of processes that together form the single system. This single system can be represented more simply using a context diagram (see below). Data flow diagrams therefore show a further level of detail not seen in the context diagram. Data flow diagrams identify the source of data, its flow between processes and its destination along with data generated by the system.

Many businesses these days cannot afford to purchase custom software; that is specially written software that uniquely solves their predefined problem. So they settle for generic



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software written to meet a general need. This software is known as application software or off the shelf software. Examples of this include the Microsoft Office Suite or MYOB (Mind your Own Business).

Implementing The implementation stage delivers the new information system to the participants. It involves using the solution to solve the problem. If a software package, such as database management system, is chosen, implementing a solution involves applying the software to the problem. The implementation phase may involve a major change in the way organisations operate. This requires conversion to the new system and training.

Conversion ………………………involves changing from the old system to the new system. It must be carefully planned and executed to avoid errors. There are four methods of conversion: direct, parallel, phased and pilot.



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Name Definition Method of conversion over time

Direct Conversion

Parallel Conversion

Phased Conversion

Pilot Conversion



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Testing, evaluating and Maintaining In order for the new system to function effectively, it requires the information technology working correctly and the participants using it effectively. People responsible for the operation of the system include computer operations and managers Briefly describe the role of each participant. Computer Operators .............................................................................................................. ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... Managers ............................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ............................................................................................................................................... ...............................................................................................................................................



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Social an Ethical Issues The Social and Ethical Issues covered in the IPT course include: privacy of the individual

security of data and information

accuracy of data and information and data quality

changing nature of work/deskilling and job displacement

Appropriate information use

health and safety

copyright laws and intellectual property accessibility considerations

Privacy of the Individual Data is stored about you on many computer systems. List some of these places:

The National Privacy Act of 2001 aims to protect the personal information collected and recorded by governments and other organisations. This covers individuals rights such as:

Secure storage and accuracy of data collected

Use of data by third parties

Rights of the individuals to access their own personal data. This last aspect is also covered by the Freedom of Information Act (1982)

The main aim of privacy legislation is to ensure businesses do not “on-sell” information to other related businesses.

Security of Data/Information People who gain illegal access to information systems are known as Hackers or crackers. In this age of information, data or information is worth money, and a hacker that can access data illegitimately can cost businesses money either in the loss of data, or the selling of data to opposition.



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Many computer crimes go unreported due to the fact that the cost of bad publicity can often be higher than the theft itself. For example, a rumour gets out that a bank is a security risk…people panic and withdraw their savings, and the bank does not have enough cash to cover the panic, they will bankrupt, even though the money is quite safe. An incident like this happened a few years ago, when a noteable radio announcer announced that St George bank were going bust. The crime may also not be reported because it is undiscovered by the owners of the information, for example, if a hacker could get in and out without being discovered. Data security involves a series of safeguards to protect data from deliberate or accidental damage. Eg. Passwords Objects (keys, keycards) Biometric devices (fingerprints, retina scans, voice ID) Data encryption (coding the data so it cannot be read by anyone but the intended user Firewalls (software protection to check data coming from outside sources) Secure paper waste (shredding of confidential data, prevent “garbage diving”) Backup regularly Screening of employees

Accuracy of Data Information/ Data quality Data errors can cause problems. Maintaining the accuracy of data information requires attention in all phases of information processing. Generally, the further along in the processes you are, the harder it is to identify errors and the more expensive to fix them Accuracy is preserved by: Collecting accurate data Ensuring the security and integrity of info

o Allowing access to only those people who should be able to change data. Audit and validate changes to the data/information

o Checking o Confirming (with the person of which the information is stored..eg, school

records, HSC subject selection, class lists) o Data validation

building controls into the data entry to ensure that data conforms to a set of predefined checks or rules eg, date= ##/##/##)

Data must meet a predefined range eg, age>0 The more times data is recorded, the more chance of inaccuracy there is. If data is recorded more than once, it is known as data redundancy. If the data is duplicated, and one is changed, which occurrence is correct). The best way to reduce data redundancy is to have a single storage location for each data. The accuracy of data collection will often impact upon the data quality.



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Changing Nature of Work The introduction of a new system brings changes in the personnel requirements of an organisation.

machines can cause 'job displacement' - the Worker is replaced by a machine. retraining may be required for the displaced worker. multinational companies build factories in countries with cheaper labour costs. computers and new technology have created, as well as replaced jobs. retraining is not always practical - not enough positions: early retirement, voluntary

redundancy, natural attrition, hours/pay/conditions are alternatives that can be investigated.

other solutions: job-sharing, lower retirement age, raising school leaving age, preparing school leavers

As a result of the introduction of a computer-based system:

the sacrifice of individual skills for improved productivity and efficiency. (deskilling of the population)

the level of skill required for many jobs has decreased. de-skilling, with a person now just controlling a computer that does the job the potential for electronic monitoring of

productivity may also result in increased worker stress and associated

telecommuting i.e. the ability to work from home. increased efficiency that generally results from the

introduction of a computer-based system e.g. office automation.

Appropriate Information Use computerisation brings large amounts of information into some hands, giving rise to

power and control issues. centralisation of data can allow greater access to information, and hence greater

power and control (this over security and privacy). people who are in a position of power should behave ethically. Who has control of your information and how can it be used? Is the data being used as it was intended when it was collected?



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Health and Safety When designing a new system, the work environment needs to be considered as the improper layout could result in injuries. The Occupational Health and Safety Act requires employers to maintain a safe working environment and protect workers against foreseeable risks. It requires both employers and employees to establish and maintain a safe environment. Ergonomics refers to the relationship between people and their work environment. It is the process of designing or arranging workplaces, products and systems so that they fit the people who use them. The work environment, and in particular the way a computer is used, can have an affect on the body (see Figure 3.38). The work environment includes the desk, chair, hardware, software, keyboard, work routine and indoor climate. The participant's relationship with all these factors affects health and efficiency. If computers are being used in the correct way, the working environment is safe and the participant will be able to work at maximum efficiency. Conversely, incorrect use of computers can cause health problems such as eyestrain, headaches, backaches, fatigue, muscle pain and repetitive strain injury (RSI). Carpal tunnel syndrome and tenosynovitis are two common forms of RSI. • Carpal tunnel syndrome (CTS) is a pinching of the nerve that passes through the wrist. It is produced by repeating the same small movements many times. Typical symptoms are numbness or burning in the fingers or wrist. CTS can cause permanent nerve damage. • Tenosynovitis is a narrowing and inflammation of the tendon sheath. It occurs when a repetitive activity exceeds the tendon sheath's ability to lubricate the tendon. Tenosynovitis causes pain and swelling in the tendons and may cause fingers to lock in one position.



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Copyright Laws and Intellectual Property Intellectual property is a term that covers different levels of legal rights. Copyright is the right to use, copy or control the work of authors and artists, including software developers. Copyright covers: Literary, dramatic, musical and artistic work, computer software,

sound recordings, films and broadcasts Copyright is automatic and instant, and does not require the © symbol. (in Australia) Copyright exists in the work whether or not the copyright is registered A work protected by copyright in one country will receive the same treatment in most

other countries



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There is no official general registrar of copyright, so it is difficult to assess who is the

actual owner of the copyright. (eg, Microsoft vs Macintosh OS…Macintosh accused MS of copying the code of their operating system, therefore breaking copyright)

Copyright protection covers the life of the author +50 years. Copyright of a work is generally owned by the person who created the work or that

person’s employer if the work was created in the course of employment (eg, a teacher’s work…copyright is owned by the school if the purpose of the work was to teach in that school)

Copyright does not stop someone from creating a work that is identical, if it is not copying

Ownership of a material object in which a copyrighted object is a part does not transfer the copyright. For example, if you buy a program on a disk, you are not purchasing the program, but rather, the right to install it and use it (under your licensing agreement)

Accessibility Concerns Information systems must be developed with a wide variety of end users in mind. People with disabilities have a need and a right to use information systems eg. A sight impaired user would like to search the electronic catalogue at their local library. Technology including screen reader software and braille keyboards help users experience the benefit of the information system.



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Chapter Review

Terms Statements

1. context diagram

2. design specifications

3. evaluation

4. feasibility study

5. Gantt Chart

6. maintenance

7. pilot conversion

8. parallel conversion

9. requirement report

10. system development cycle

11. Data Flow Diagram