Touch Screen
When Tesco need to be able to enter information manually into a till computer, needed to complete transactions at the end of a customer’s shop, they use a touch screen. This is an input device, as it allows people to enter (or input) information into a computer. It works by having a touch screen sensor, which is a panel made out of clear glass, and its surface is touch responsive. This goes over the display screen in the EPOS system that the employee at the till has access to. When the relevant area of the screen is touched, the electrical signal going through the device changes because of the contact. The computer can work out from this where the screen has been touched. Another necessary part of the touch screen is the ‘controller’. This is a PC card that links the PC and the touch screen. The information entered to the touch screen can be interpreted by the controller into information that can be processed by the PC. Most touch screens are designed to emulate the actions carried out by a mouse; touching the screen is the equivalent of clicking the mouse. This means that this device can potentially be used with existing software, because of this similarity. It is used along with the EPOS Software, because that is what reads the information entered in the first place. The stock control database is also used in conjunction with the touch screen, because information entered using the touch screen (for instance the product number if it has been entered manually rather than read by the laser scanner) needs to be sent to the database, so the information needed, like the price, can be accessed. The strengths are that it is a really easy way to enter information, and that it is not as intimidating as some other methods of inputting information can be. The weaknesses of touch screens are that it could be difficult selecting small items on the screen, so the large ones that would be required would take up more room. Accidents could also be made easily, for instance a button is pressed twice, and a customer is charged double what they should be. An alternative would be a normal computer keyboard. Tesco don’t use this alternative because it would increase the size of the work station required by one worker; not just a screen, but a keyboard as well. Keyboards also break fairly easily, and, working in a shop that sells groceries, it may be in danger of being damaged from some kind of liquid, or getting things stuck between the keys. This meets the aim of staff satisfaction, because they will be happier with their job if they are required to work an easy to use device.
Mouse
A mouse is an input device used for inputting information into a system. There are a few types available, including a rollerball, which works by detecting when a ball contained in the mouse’s casing moves forwards and backwards, and a laser mouse, which contains a laser which detects movement.
Keyboard
A keyboard is also an input device used for entering information into a system. It consists of keys with functions on them, cursor movement, letter keys, a numeric keypad, and editing keys. Most keyboards have about 102 keys on them, and are called ‘QWERTY’ keyboards because of the first six letters on them.
Output Devices
An output device allows information to leave a computer system. Lots of output devices are used by Tesco within their EPOS system, like the receipt printer and LED display. I am going to look at both of these in detail.
LED Display
(Light Emitting Diode)
When Tesco need to display information to customers, they use an LED Display. This is an output device, this is because it lets information be outputted and viewed by the customer. It works by lighting up sections of the display to form words, numbers, symbols etc. that can then be read by Tesco’s customer. A diode is a device that causes an electric current to flow in one direction. It is a very simple type of semiconductor, a component used in many electronic circuits that acts as a poor conductor, but not an insulator, of electronic charge. A Light Emitting Diode lights up, or glows, when electricity is passed through it. Information is sent from the main till PC telling the display what information needs to be shown, and this is translated into points of light displaying key information. The sort of information shown is the name of the
last product that was scanned, it’s
price, and the running total. It is
used along with the stock control
database, as that is where the
information it is designed to display
comes from. The strengths of the
LED display are that it is a simple
way to allow shoppers to view
information about what they are
buying, and it lets them know how
much they have spent so far. The
weaknesses are that if a few diodes
were to break, it may prove really
hard to read what was appearing at
all. Also, there is a limit to the size
your average LED display could be,
so names of products may have to
be abbreviated or shortened so they could fit. An alternative would be a device that’s more lie a mini computer monitor, on which everything you’re buying and the price comes up. Tesco don’t use this alternative because it wouldn’t be as cost effective as the LED display, which tells you what you need to know without being overly-complicated. This meets the aim of customer satisfaction, because they can easily see what they are buying, which would be appealing if you wanted to make sure you know exactly what you are spending your money on, and ensure you didn’t mistakenly pick up a product that you don’t really need.
Receipt Printer
When Tesco need to provide customers with a record of the transaction they have made, they use a receipt printer. Receipts are useful as proof of purchase; if there’s a problem with the transaction, there is evidence that it took place. For instance if a product needs to be returned, the receipt is usually necessary to prove that it was bought, and when and where. This is an output device, as it produces (or outputs) a hard copy of information from the EPOS computer. It works like a normal printer in that it is sent information by the computer specifying the information that has to be printed. The main difference between receipt printers and normal printers is that the method used to print receipts is different to normal inkjet printers, and receipts need to be printed faster, as a customer would not want to wait for too long before their receipt is ready. The paper is also thinner and comes in a roll, and needs to be heat sensitive, because receipt printers are thermal printers, which means that heat is applied using printer pins to the heat sensitive paper, so it goes darker in the places where this heat is applied, to form words and numbers. The information usually contained on a receipt are all of the products bought, the prices of these products, and the overall price. They also have the name and details of the shop where the transaction took place, in this case Tesco, the date, and sometimes
the name of the employee who served
you. All cashiers have to do is instruct
the computer to print off a receipt, and
it will do so automatically. The receipt
printer works with the touch screen, as
that is where the cashier enters the
command for the printer to print off a
receipt. It is also used with the stock
database, as this is where product
information on the receipt comes from.
The strengths are that it is quick, which
is vital as customers can’t be expected to wait for large lengths of time, and the information needed is displayed clearly. The weaknesses are that it is not particularly environmentally friendly, as it uses up paper, and if the customer were to misplace the receipt, but then need it later, there is no backup like their would be if it was all electronic. An alternative to a receipt printer would be a normal printer. This could do the job fairly efficiently too. Tesco don’t use this alternative as it would be even less environmentally friendly than the receipt printer, as the thicker paper used would need more trees to be produced than thin paper would, and most receipts are thrown away. Normal printers are also not as cost effective; ink and maintenance for receipt printers are much cheaper than normal ones. This is important as Tesco should save money where they can so they have more available to spend on more significant areas of the company, such as high-quality stock. This meets the aim of customer satisfaction, as it allows customers to check the products they
have bought, and how much they all cost, and receipts are also useful for tax purposes.
Monitor
A monitor is a device that can output information. It is a screen used for viewing whatever information is needed. It can display (or output) the electronic signals being sent to it by a computer by translating them into images, so that they can be viewed by whoever is using the computer.
Touch Screen
There are many types of output systems in the EPOS system, used by Tesco. The touch screen can be an input, but also an output device. It displays images in a similar way to a monitor, but you can control it using the touch sensitive layer on top of the screen.
Storage Devices
Storage devices are the methods by which information is stored digitally on or for a computer. Tesco uses Backup memory and Hard Drive. Magnetic tape saves information similarly to cassettes, whilst hard drives cannot generally be removed, and contain data from a computer.
Hard Drive
When Tesco need to store important data, they use a hard drive. This is a storage device because it is used for saving digital information. You can buy hard drives for anything upwards of around £50, and they work by using disks, or ‘platters’, sealed in a case to protect them, that spin at extremely high speeds, at least 7,000 revolutions (rotations around the centre point) per minute inside a computer. Computers read them in binary code, which is a type of code consisting of ones and zeroes that can be read by computers and translated into the letters and digits they represent. Information saved on a hard drive is read back by the detection of the magnetization of the material that it is made out of. It is safe to store important data on hard drives, as you cannot easily delete what is stored on it because it is non-removable. It can also store more data than many equivalents, such as a floppy disk or memory stick. It has a large memory, and most HDDs (Hard Disk Drives) can store between 160GigaBytes and 1TeraByte of information. Because of this, it is good for storing important information so it can be used as back up just in case something were to happen to the copy of data used usually. Tesco’s hard drive is used to store essential information on each till PC and the information from the till, like the transactions that have taken place. The hard drive is linked to most of the rest of the system because other aspects of EPOS are saved onto the hard drive. It is, for example, linked to the laser scanner, because the laser scanner enters product information, which is later saved by the hard drive. The strengths of hard drives are that they have a big memory and can store lots of data, and they are secure. These are both important qualities for Tesco. They are also better value than buying many storage devices that would hold the same amount of information as a hard drive would, for instance lots of memory sticks. Weaknesses are the price of hard drives, they do cost a lot of money, even if they hold lots of data, particularly if it is a hard drive with a large memory that is required. This would have a negative effect on Tesco because that means less money for them to spend on other aspects of the company. Hard drives are also not particularly versatile in that they are not removable, so you cannot use them wherever, which is not particularly convenient. An alternative would be a USB stick, or another type of storage device. These are better in a way because they can me moved around, and are quite a lot cheaper. But Tesco would get less for their money if they went down this route, as memory stick memories are not as large as hard drive ones. That is why Tesco do not use this alternative. This meets the aim of staff satisfaction, because the information necessary for employees to do their job is saved securely.
Backup (Magnetic Tape)
When Tesco need to back up data they have collected during the day, they use magnetic tape. This is a storage device, as it is used to save information. It works by being recorded on in a tape drive. Unlike hard drives, magnetic tape has to be read in the order it’s recorded in; you can’t pick and choose the information you want to access. This isn’t strictly speaking as efficient, but it can store loads of details. An advantage of magnetic tape is that it is cheap, a lot cheaper than hard drives. This isn’t false economy, however, as data stored is even harder to delete, so it’s really secure for important files. The fact that they are so cheap frees up money for Tesco, and it’s useful if Tesco can save money in areas such as this to be used for other aspects of their stores. A major disadvantage is the amount of time it takes to save or view information that is needed, because you have to go through all the data in order until you get to
whatever it is that you need, so the reel it’s on has to
keep turning round in order to read or write data. There
are much faster alternatives, so if it wasn’t for the other
benefits of this method, it might not be worth it. But the
amount of time it takes to find data is a big disadvantage.
Like with the hard drive, an alternative would be to use
a USB device to store information on. One of the most
common types are memory sticks, and this would solve
the problem of how long it takes to find information. This
is a much quicker, more efficient way of saving data. In
a situation where information is needed urgently, this would make much more sense. USBs, however, need someone pressing buttons to save information, unlike tape storage, so more employees are needed to save files. USBs also cost a lot more than magnetic tape, although they are cheaper than hard drives. So the cost factor would stop Tesco from using USBs instead. They meet Tesco’s aim of promoting sustainability, as they are actually environmentally friendly, due to their small amount of packaging. They also help achieve other aims by being cost effective, so Tesco can spend money on supplying good value produce, another significant aim.
Processor and Main Memory
Main Memory
All computers have a main memory, which uses temporary and permanent storage. Main memory is made up of both RAM and ROM together, as they both do different jobs. RAM stands for Random Access Memory and ROM is Read Only Memory.
RAM and ROM
(Random Access Memory), (Read Only Memory)
When Tesco need to store information, they use RAM and ROM. This is a storage device because it is used for saving all the information needed by EPOS. All computers need storage devices so that they are able to store information for future use. But computers also require something to save information that is currently being used. That’s what RAM does; it works by only holding information while the computer is turned on. It is the ‘temporary’ memory. If the computer in question was turned off without the data being saved, or if it crashed, the RAM would not store it. For this reason it is sometimes called ‘volatile’ memory. It comes in the form of integrated circuits that can be accessed and transferred without physically moving what it is being stored in. RAM is useful because it is normally easily upgraded, in the form of a small module called a ‘memory stick’ or ‘RAM stick’. These are also relatively cheap, with a new 2GigaByte stick costing anything upwards of about £10 or £15. RAM speed is measured in nanoseconds, or ns, and the less ns there are, the faster RAM can work. Modern ones can run at 60ns and faster, which is much quicker than it used to be. Generally, the smaller the amount of RAM a computer has, the slower it will run. The more it has, the easier it is for the computer to cope with a lot of things going on at the same time, for instance a lot of programs open at once, and it will not have a problem with working at its normal speed. In Tesco’s RAM, there would be things like unfinished documents still being typed (such as letters to customers) and lists of products that are still being scanned. Whatever is currently being displayed on a computer screen is usually saved on RAM. In contrast, ROM is not usually upgraded at all, as it would be difficult to change. If you want to change it, you have to open up the computer and change the ROM chips inside it. What ROM does is offer a safe place to store vital information and programs. They could be saved to a hard-drive, but would not be as secure, because there is a chance they could be deleted, whereas with ROM, this is virtually impossible. Whilst RAM is called ‘volatile memory’, ROM is known as ‘non volatile memory’, as information stored on it is safe even if the computer’s power supply is cut off, or if it crashes etc. This information is effectively permanent, so even if a user were to attempt to modify it, they wouldn’t be able to. Data usually saved to ROM includes the information instructing the computer on how to load the operating system when it’s turned on; it is important that this is never lost or damaged. Tesco use ROM to save the information they need to load their operating system, and to save the programs necessary to perform the functions carried out by EPOS. RAM is used along with the touch screen, as it stores whatever is being displayed. The advantages of RAM are that it is an effective way to store data currently in use, as it allows Tesco to perform tasks easily and quickly, provided there is enough of it. The disadvantages are that it is, as I have mentioned, ‘volatile’, so if something goes wrong with your computer, or it is accidentally switched off, there is no guarantee that the information saved to RAM will be recovered. The advantages of ROM are that it is about as secure as you can get. It’s really hard to damage what is stored on ROM. On the other hand, this is a disadvantage, because if you really want to change something saved on ROM, it’s really hard to do. An alternative would be to use a hard drive instead, but Tesco don’t use this alternative as ROM is much more secure, which is preferable. This meets the aim of achieving staff satisfaction, because if the memory is effective, as RAM and ROM are, staff will not have to work hard to try and retrieve lost information, or be unable to store information they need to store.
Processors or CPU
(Central Processing Unit)
When Tesco need to process information, they use processors. They don’t really fit into a category, as they are not input, output, or storage devices. They work by carrying out programmes, which are a set of instructions that perform a certain job. Programmes are the jobs that need to be performed so as to fulfil a task. They are stored in the form of numbers, which are then decoded when the computer needs to read them. The speed at which this occurs depends on how high the speed of the individual processor is. The greater the speed, the faster the processor is able to operate. Processor speeds are measured in GHz or MHz (gigahertz and megahertz). New PCs have processor speeds of around 2 or 3 GHZ. All programmes can be processed by CPUs, whatever their size; some examples of types of processors would be Celeron, Pentium and Intel. Processors are expensive, prices vary from a few hundred pounds to a few thousand, depending on their speed. Tesco need processors so that EPOS can function, without them EPOS wouldn’t operate. It’s used along with the memory, as the memory stores everything controlled by CPU, and the whole EPOS system is controlled by CPU, so it’s linked to the other components. The advantages of CPU are that even though it is so small, it still performs all the processes that have to be carried out. They are reliable, and really fast (depending on the individual processor’s speed). The disadvantages are that because CPUs are so vital, if something does happen to go wrong it affects the whole system; if it were to break the computer would be useless until the processor is replaced. If this were to happen, you would need a whole new CPU, which can be really expensive. There isn’t really an alternative to using a CPU and EPOS, Tesco would have to come up with a completely different system. They could arrange a manual system, which would be good as it wouldn’t be so reliant on one thing. Tesco don’t use this alternative, however, as it is much less efficient than EPOS, and wouldn’t be a good use of cashier’s time. Processors meet Tesco’s aims of staff satisfaction, because it means that the computers they are required to use are quick and work well, and also customer satisfaction, as customers need wait for the minimum amount of time at the checkout when the EPOS system is used.
Ports and Cables Used in the EPOS System
Below are all the ports and cables that are used.
Parallel
These are used to connect most modern
printers to your PC, but some printers use
USB instead. It’s called ‘parallel’ because
it refers to processes that are all happening
at the same time.
PS2
These are used to connect mice and keyboards,
and are sometimes colour coded; green for mice,
purple for keyboards. This is important, as you
need to be careful to ensure that you plug the
right device into the right port. They have six pins,
and are fairly slow.
Serial
Some specialist devices use this,
along with some less modern mice.
They send data quite slowly, and
some things such as printers can
be called either ‘parallel’ or ‘serial’.
SVGA/RGB
(Super Video Graphics Array)/(Red, Green and Blue)
Sends Video Data from a PC
to a monitor, and also to other
devices that output images like
LCD monitors (they are lighter
and use less power than a CRT
monitor).
USB
(Universal Serial Bus)
Used to send and receive information at considerable speeds to and from a range of devices. USB’s are now turning into the accepted means of doing this, for all recent input and output devices. There are two types, USB1 and USB2. They are two different types of ports, and USB1 is much slower at downloading music etc than USB2. USB 1 works at about 12Mbits/second, and USB2 at 480Mbits/second. The main advantage of USBs is the sheer speed of them. As a rule, they’re really fast. A disadvantage is that as they are still pretty new technology, you can’t use them on older computers. An alternative would be to use a hard drive for storing information instead, but this is not as versatile since it cannot be moved around in the way that USBs can. USB devices help Tesco meet the aim of staff satisfaction, as when employees need to load or save something, they are able to use a USB, and USBs are fast and easy to use.
RJ45 (network cable)
Category 5 cables can be used with
this for network connections. Network
information can be transferred quickly
using an RJ45 cable.
http://www.innosolu.com/usb_adapters1.html
Network Cable
When Tesco needs to use the connection between computers, they use a network cable. This isn’t really a storage, input or output device, as it connects a series of devices. It works by connecting computers, and also other devices. Connected computers can share hardware, software and data. Tesco have a network within each store, connecting computers in each shop, and a much larger one connecting all of Tesco’s stores’ computers. So all of Tesco’s printers, till PCs etc are connected somehow. To achieve this, they use an RJ45 cable. The advantages of computer networks are that information is easily accessed from any computer on the network, and can be modified and saved via whatever computer is being used. They are also very secure, so they are unlikely to be hacked into, while at the same time they are available to anyone working in the Tesco store who needs access to this information. A disadvantage is that because the computers are all connected, if one gets a virus, it could be spread more easily to other computers. An advantage of using network cables is that information passes very quickly through them A disadvantage is that because cables and wires are used in Tesco’s network, there are a lot of opportunities for them to break, and it would be hard to move a computer then plug it back in. Instead of using cables to connect their devices, Tesco could use a type of wireless network. This would be good as all the connected devices would be much more portable. So all that is needed is a wireless receiver, as opposed to lots of wires and cables. Tesco do not use this alternative as it is not as fast as their present system. It’s also not as secure, so it would be easier to hack into Tesco’s network. This could be really dangerous if any of Tesco’s customer details could be accessed by anyone else, because identity theft is a big problem, and customers could become vulnerable to that. Network cables help Tesco meet the aims of customer satisfaction, because any of their details are kept safe, and the information about the products they may want to buy can be found in the stock database, which is used in conjunction with the Tesco network, and staff satisfaction, because information employees are required to be able to access is easily available, and they are unlikely to have any problems regarding information saved on the network.
Application Software
Application software is used a lot in Tesco, and is a type of software that is used to power individual programmes on a computer.
Database
When Tesco need to access information about their stock, they use their stock control database. It is software, because it is not an indivdual part of EPOS, but a programme on the system. It works by keeping all of the product information in one big database, so when data from it is needed, it is accessible from the stock control database. If a product is scanned, or it’s product number manually entered into the computer, it’s details will be accessible. Every item sold by Tesco can be found on the database, and details like its supplier, price, how many are available, and any special offers that may apply to the product. It is connected to all the computers in Tesco stores, and when a product is scanned, the stock number on the database decreases. It is used along with the receipt printer, as information included on the receipts is found on the database. It is also used with the laser scanner, as when products are scanned, their information can be found on the stock database, and the LED display, to provide the information shown. The strengths are that all the information needed can be found in the same place, and the database is an efficient method of finding the information. It is also useful that the stock is automatically deleted from the database, and it lets you know when more needs to be ordered, so everything is done on the computer. The main weakness is that if there is an error, it affects every computer using the database, and not just the one on which the error was made. If it breaks down at all, there is not another effective alternative. An alternative would be to manually check the stock, and record how many products have been solved, and have product details listed somewhere available to all employees. As long as it is handled efficiently, this could work, but it is not as reliable and easy as the database is. It is also more time consuming. So Tesco usually rely on the database. This meets the aim of staff satisfaction, because cashiers don’t have to record information manually. It also achieves customer satisfaction, because a more labour intensive method would leave them waiting around for longer. It is also an environmentally friendly option, as no paper is used if the whole process is electronic.
EPOS Software
(Electronic Point Of Sale)
When Tesco need complete a sales transaction they use EPOS, which requires system software to work. This is system software, as it gives instructions to the rest of the system to tell it what to do. It is accessed when the cashier enters a number that allows the system to identify them. Then the employee can continue to use the laser scanner to scan products, or physically enter the product code. Once this detail is entered, the software allows the product to be looked up on the stock database, which contains all the information needed about all the products Tesco sell, such as the product supplier, price, and amount in stock. Then the appropriate information can be retrieved, like the price, and the stock is reduced by one. This is repeated with all the groceries the customer wants to purchase, and all their details can be saved. Databases are a very clear way of displaying information, and Tesco’s is a significant aspect of EPOS. When all the products have been scanned, the software sends an instruction to add up the prices, and calculate the change due etc. It is used along with the receipt printer, because the software sends the information that needs to be printed to the printer, and also the LED display, because prices appear on this, and the prices are retrieved from the stock database, which requires EPOS software to function correctly. It is also used with many other parts of EPOS, such as the laser scanner and touch screen, as they are methods of entering the information needed to find the product on the stock database. The strengths are that it is simple to use, and EPOS software is fairly consistent and reliable too. Weaknesses are that if one mistake is made on a computer, like the wrong product being scanned due to human error, it affects the stock database accessed by all the other employees. Also, if one element of the system goes wrong, because of a virus for instance, then it’s all affected An alternative to EPOS Software would be to perform all the functions
manually, with all the information needed written down.
This would be even more vulnerable to human error
than EPOS Software is, and would be very inefficient
and time consuming. Tesco don’t use the alternative
for these reasons. This meets the aim of staff
satisfaction, as they have an easier job if they can
access all the information they need to in one place
on the computer. It also means customers waiting time
is as short as possible, which contributes to staff
satisfaction.
Evaluation
The components that I have covered together make an ICT system. The system software tells everything what to do. The hard drive stores programmes needed to run the system properly, and all the other data needed, for instance the stock control database. That contains all the products and their details. Some data is backed up, on magnetic tape, and sends information to the receipt printer and LED display, which can show customers details of the products they are buying. This all helps achieve customer satisfaction, as they can view the products they have bought as they are being scanned, and have a hard copy to take home with them. Information can be inputted using the touch screen, and products are scanned using the laser scanner, which scans barcodes. This meets staff satisfaction, another aim, because the speed and simplicity of this process makes their jobs easier. All the computers are connected in a network using an RJ45 cable, which helps information to be computed and communicated to other computers and shops, and generally allows Tesco to function properly, and hopefully meet all their aims in the process. These all contribute to a successful transaction in Tesco.
The EPOS system helps Tesco to provide staff and customer satisfaction, and be as environmentally friendly as currently possible. It is designed to result in minimum waiting times, and pleased staff and customers. Tesco can now continue to expand their international company with a successful computer system and positive aims for the future.
Bibliography
http://en.wikipedia.org/wiki/Read-only_memory
http://www.gcse.com/ict/epos.htm
http://www.karbosguide.com/hardware/module2e1.htm
