- Created by: AnjaleeHari
- Created on: 01-10-15 09:30
Problem Identification is seeing the problem before trying to solve it, then consider what software skills you have. This is the first strategy in solving the problem.
- 1. Describing in detail what the problem is that you aim to solve.
- 2. Identify who actually needs the solution and details as to why they client needs the solution.
- 3. Identifying the users of the solution - the people who make active use of the system.
- 4. Who is the audience? - the people viewing the solution.
- 5. Producing a list of client requirements by asking the client about identifying what they want in the new solution.
- 6. Word Processing findings into a professional report.
SDLC - System Development Life Cycle
- A process of stages which occur during the devlopment of a new ICT system, by following a number of ordered stages to avoid any development problems.
Why is analysis important?
- To ensure that all the user requirements are met in production.
- Allow them to find and address problems with existing solution.
- Analysis of problems that have an ICT solution involoves understanding the inputs, process and outputs.
- A request that the client needs within a new solution.
- The solution is for them and not for you.
- You need to find out exactly what they want.
- Before creating a new system, you will need to find out the client requirements.
- You can only do this by asking them.
- Develpoers must create check to lesen the likelihood of a suer entering incorrect information when developing a solution to an ict problem.
- Design tools are the software you use to provide a solution to an ict problem.
What documentation needs to be produced for the implementation stage?
- A problem identification with a list of requirements for that problem.
- Intepretation of those requirements as inputs, processing and output
- A test plan and clearly annotated samples of testing evidence that is cross referenced to the test plan.
THE IMPLEMETNATION STAGE WILL MAKE USE OF:
- Hardware - Input, storage and output devices
- Software - Software tolls used to create the solution to the problem.
- Communication technologies - solution may make use of a network or the internet
It is useful to produce evidence such as:
- Printouts (with annotations)
- Sound Recordings in a suitbale format
- Photographs / images and text
Implementation part 2
During implementation, you need to keep a record of any changes made to your design.
- Always keep looking at the client requirements to check that they are being met.
- Make usre that you use the previous stages ie. analysis and design stages.
- Ensure that validation checks are built into the system or other ways to ensure that accurate sata is being processed.
Why is testing useful?
It is useful becasue it highlights the key areas of errors and allows the user to make improvements to increase efficency in thhe system.
Why is it important that client requirements are tested?
To make sure that there is no issue with any of the client requirements sue to the client paying for the solution. This results in the system being throughly tested.
There are 5 different reasons for testing. Each test that is completed for a new solution should fit into one or more of these reasons.
- 1. Validity of data input
- 2. Accuracy of output
- 3. Presentaion of output
- 4. That the solution meets the client requirements
- 5. That the solution is usable by the end user/ or intended audience
The ideal way of entering data into an ict system would be for it to be:
Unfortunately, it is hard to find a way in which satisifes all criteria, so a compromise has to be reached
CAPTURING TRANSACTION DATA
MAGNETIC ***** RECOGNITION
- Can be seen on credit cards and debit cards
- Also found on plane tickets and train tickets
- Data is encoded in the magnetic strips
Input devices part 2
- Allow selections to be made by touching the screen
- Simple and can be used by almost anyone
BAR CODE RECOGNITION
- Uses a series of light and dark bars of different widths to enter a code
- Can be used to determine where a product is within a database
OPTICAL MARK RECOGNITION (OMR)
- Readers can read marked sheets at typical speeds of 3000 sheets per hour
- Ideal way of marking multiple choice question papers
OPTICAL CHARACTER RECOGNITION (OCR)
- Uses a scanner as the input device along with special software which looks at the shape of each character to be recognised
- Software converts each letter to text
Input devices part 3
MAGNETIC INK CHARACTER READER (MICR)
- Numbers are printed onto the bottom of the cheque in special magnetic ink
- It is then read at high speed using a magnetic ink reader
Some times the output of one ICT system can be used as the input media for a different ICT system e.g. lottery number selection on a form , you are then given the form with a bar code on it, the receipt can be used to assess you winning.
- Forms with marks on them capable of being read by an optical mark reader
- Forms containing text capable of being read by an optical mark reader
- A bar code
- A magnetic ***** on a credit / debit . Loyalty or membership card
- A CD – ROM used to supply the printer driver for a new printer
- A bar code on a bin so the council know how much rubbish you throw away
Output Devices and Methods
The most popular output devices used are the screen and the printer. However, there are many other output methods out there. For example, to display a multimedia webpage, we could use a screen and speakers can be used to output sound. In addition, output can be used from one system and transmitted or saved to be used as input by a different ICT system. This is known as “output in a digital form”. Below are a few other examples of output methods: -
- Hardcopy – printed on paper/card.
- Soft copy – displayed on screen.
- Sound – speech, music, sound effects, output to portable devices such as iPod, Mp3 players etc
Once data has been entered, stored and processed by an ICT system, the results of the processing are then output using a type of output device. There are a number of output devices available, the most common being different printer types: -
There are several different types of printers available, each suited for a particular purpose. The main types of printers include: -
Output Devices and Methods part 2
These are popular within the home environment and less popular in business due to the high cost of the ink cartridges. Ink-jet printer work by spraying ink onto the paper and often can produce high quality/professional like printouts. Ink-jet printers have a number of advantages and disadvantages such as: -
- High quality printing – ideal if it is required to print something where appearance is important.
- Produce good quality photographic prints – ideal for developing photos or brochures.
- Quietness in operation
- Cheap to buy as the initial cost to buy an ink-jet is low.
- High cost of ink cartridges or refills.
- Ink smudges can be an issue.
Output Devices and Methods part 3
A requirement for high quality paper – this is particularly true if you are looking to print out high quality photographs. For this, you may have to purchase glossy paper.
These are popular within businesses because of their high speed when printing in colour or black and white. They make use of photocopier technology and different coloured inks. Laser printers have many advantages and disadvantages such as: -
- Ink supplies last longer
- High printing speed – ideal in an office environment where large quantities of black and white printouts are required.
- Reliable – laser printers often have fewer problems compared to ink-jet printers e.g. less likely for the print nozzles to get blocked.
- No wet pages.
- No special paper requirements.
Output Devices and Methods part 4
- High initial cost to buy a laser printer
- Colour printing can be expensive as you have to use a colour laser printer
- High power consumption – meaning running costs are higher.
Dot matrix printers are not often seen in the home environment, but are commonly seen in businesses. They are called impact printers because they work by hitting little pins (normally 9-24) against an inked ribbon to mark out the characters.
Thermal printers are printers in which use heat in order to produce an impression on paper. Typical applications for thermal printers include: -
- Printing receipts in cash registers or point of sale terminals.
- Printing tickets in a multi-storey carpark.
- Printing a lottery ticket.
Output Devices and Methods part 5
Thermal printers are becoming popular owing due to their silent printing and high speed, quality printing.Multifunction printers are popular because they combine the following: -
- Printer (laser printer)
In addition, they also have a number of advantages that include: -
- Takes up little space compared to ordinary printers, fax machines, photocopies etc.
Hardware such as printers, scanners, camera’s etc., often come with software in the form of a CD-ROM or even from a website via a downloadable link. Drivers are an important part of any hardware that is linked to a computer, as they are a piece of software that converts commands from software into a form that the hardware can understand. For example, a printer driver is a program that controls the operation of a printer by feeding the printer with commands that the printer understands, once a document has printed.
Output Devices and Methods part 6
It is important to distinguish the difference between output devices and output methods. In this text you will examine a range of other possible output methods and devices other than a printer. Some examples include: -
Sometimes known as VDU (Visual Display Unit), used to view processed information. Screens today are flat, offering the advantage of taking up less space, being lighter in weight and producing less heat due to using “liquid crystal display” technology. Previously VDU’s were typically bulky and often generated a lot of heat due to their in-built cathode ray tube screens. Different screens can be used for a variety of reasons. For example, large screens are used if detailing needs to be clear (particularly in computer aided design (CAD) or desktop publishing work.
Output Devices and Methods part 7
Speakers/headphones play a role in terms of output devices and have many uses such as: -
- Listening to voicemail
- Listening to radio stations anywhere in the world
- Listen to music
- Watch/listen to videos
- Really useful for multimedia presentations/websites/quizzes*
- Make and receive phone calls over the internet. Music also needs to be portable, so that people can store or download music onto their computer before transferring it onto other devices such as iPods, Mp3’s etc.
3. Output Media: This is material where information can be stored or conveyed. The following are examples of output media: -
- Hard copies (i.e. output printed on paper, card etc.)
- Magnetic media (i.e. flash drives, picture cards, removable hard-drives)
- Optical media such as CD-ROM, CD-RW, DVD etc.
Output Devices and Methods part 8
Examples of control signals:
- Lights such as LEDs (Light Emitting Diodes) can be connecte4d to a computer or within equipment and respond to electrical signals which tells them to switch on/off
- Control devices such as lights, buzzers and motors are used when the computer is controlling a situation such as Traffic lights.
- Modern printers make use of light up icons to indicate when ink/ toner is low. These lights are controlled by the microprocessor inside the laser printer.
An output device is a piece of hardware that is used to display or output data which has been processed or has been stored on the computer. Sound as an output methods is anything that can be heard for example speech, music and sound effects on portable devices such as MP3 / MP4 devices. Speakers are a very important output device and are used by many users in different ways. For example, speakers can be used to: -
- Listening to voicemail
- Listening to radio stations anywhere in the world
- Listen to music
- Watch/listen to videos
- Make and receive phone calls over the internet.
Output Devices and Methods part 9
Headphones are an alternative to speakers and are often used in order to not disturb others.
A digital photo frame is a picture frame that outputs digital photos displayed on its screen without the need of a computer or printer.
Pictures taken from a camera could be stored on an SD card, which can then be inserted into the digital frame for the images to be read and displayed.
Large retail chain may have an ICT system in place that produces a detailed report of their sales figures for the week, month or year.
Instead of printing this out, the sales figure information could be fed into another ICT system (such as a management information system (MIS)), for managers to monitor trends and make decisions on whether more stores should be opened up elsewhere.
Output Devices and Methods part 10
Examples of such devices include: -
oGPS (Global Positioning System) – This device consists of touch screen technology whereby users can make selections from the options available, as well as enter key data in such as the a destination postcode. The screen can also act as an output whereby a route to the entered destination will be displayed and sound is also provided, in the form of directions being provided verbally.
oHeadsets that consists of speakers and a microphone – Gamers and call centre users often make use of these devices to communicate with other users by speaking into the microphone and listening via the headphone as output.
oInformation Kiosk – similar to that of a GPS system, an information kiosk also makes use of touch screen technology allowing the users to interact by selecting options throughout the system. The screen is then used as a form of output, whereby information is displayed for the users to read.
ICT systems need to store data and programs using either:
- Primary storage (using chips inside the computer)
- Secondary storage (storage outside the computer).
Primary storage is of two types:
- ROM (Read Only Memory)
- RAM (Random Access Memory)
Any data and programs that are not running on a CPU (Central Processing Unit) are stored in secondary storage. Flash memory and flash Drives are examples of secondary storage. Secondary storage is non-volatile, meaning the data can be retained when the power of the computer is switched off. Sometimes secondary storage is known as “Backing Storage”. This refers to storage that is outside the CPU and in many cases is removable, so that files can be transferred from one location to another. There are a number of storage devices and media to choose from when it comes to saving documents and files.