ICT Class Tenth Meeting

System Analysis - Analysis Stage and Design Stage

SYSTEM ANALYSIS 

A system analysis is needed to improve an existing system. The figure on the right shows the steps in taking a system analysis.

A. ANALYSIS STAGE

• This analysis stage can be done in some steps:
• collecting data from the current system
• establishing the inputs, outputs and the processing done in the system
• problems identification
• agreeing the objectives with the customer
• identifying and agreeing the customer’s requirements
•  interpreting the customer’s requirements
• producing a cost-benefit analysis
• producing a data flow diagram.
• The fact finding stage which is the first stage in analysis stage can be done in 4 different ways:
• Observation 
• Advantages: inexpensive and reliable
• Disadvantages: workers may feel uncomfortable being watched and they might not do what they usually do
• Questionnaires
• Advantages: quick and inexpensive
• Disadvantages: inflexible and the number of returned questionnaires is very low
• Interviewing
• Advantages: flexible and reliable
• Disadvantages: interviewee cannot remain anonymous, time consuming and expensive
• Looking at existing paperwork
• Advantages: much information needed is obtained
• Disadvantages: time consuming and expensive overall

B. DESIGN STAGE

• After analyzing is done, the next stage is to design the recommended system for improvements. Here are the tasks that needs to be done:
• designing data capture forms/input forms
• designing screen layouts
• designing output forms and reports
• producing systems flowcharts and/or pseudo code
• selecting and designing validation rules that need to be used
• selecting the most appropriate data verification methods
• designing and agreeing the file structures and tables
• selecting and designing the hardware requirements
• selecting and designing the software requirements
• producing algorithms or program flowcharts
• designing a testing strategy/plan.
• There are 2 important tasks in design stage: 
• Verification - a way to prevent any errors that may occur during data copying process
• Double entry
• Data is entered twice by different people
• The computer compares 2 entries
• The computer identifies any differences
• Validation - data is checked to see if it satisfies certain criteria when input into a computer

ICT Class Ninth Meeting

Banking Applications, Expert System and Library System

A. BANKING APPLICATIONS

1. Automated Telller Machines (ATMs) 

Customers can take their money, transfer or top up their phones using ATMs. This summarizes the process taking part in the ATMs

• As a customer puts his/her debit or credit card inside the machine, a contact is made to the bank's computer. 
• The customer then enters the PIN using the keypad. The PIN will be checked if it is correct and the card will also be checked if it is valid. 
• The customer will then select the cash option and the amount of cash will also be selected. 
• The customer's account is checked if the card has sufficient amount of cash to be taken and if the customer is crossing the limit of daily withdraw. 
• The customer is asked if they want a receipt. 
• The card is returned and the transaction is done. 
• The money is now dispensed and the amount of money taken will be updated.

2. Internet Banking

3. Chip and PIN 

Credit cards are mostly  equipped with a magnetic strip which contains the data. Below is the process taking on when a customer pays for a meal in a restaurant using a chip and PIN card. 

• The customer will give the waiter his/her chip and PIN card to the waiter which will be inserted inside the chip and PIN by the waiter.
• The card is checked if it is valid.
• The transaction will be terminated if the card is invalid.
• PIN is entered by the customer and if the PIN is correct, transaction will be continued.
• The transaction can be proceeded again if the card has enough funds.
• It will then be authorized and the authorization code will be sent to the restaurant.
• The price of the mean will be reduced from the bank account of the customer and the same amount of money will be given to the restaurant. 
• A receipt is printed as a proof of the purchase.

B. LIBRARY SYSTEM

• As technology is developed, libraries are now controlled using computer. This usually involve the use of barcodes in the borrower's card and in the book too. 
• There are 2 types of files stored in most libraries:
  
• Borrower's files
• Borrower's names
• Borrower's details
• Borrower's number
• Barcode of the book borrowed
• Book's files
• Barcode
• Book title
• Name of author
• Date of published
• Number of books
• Date due back
• The process taking place during book borrowing is: 
• The barcode of the book borrowed is scanned
• The books details will then be found in the book's files
• The borrower's barcode will also be scanned 
• The book files and the borrower's files are linked and updated to indicate which book is borrowed and when is the due date

C. EXPERT SYSTEM

• Expert system is used for:
• diagnosing a person's illness
• diagnostics
• chess games
• tax and financial calculations
• How expert system works:
• The information needed for the expert system is from an expert which is interviewed. 
• Data is then collected from them
• Knowledge base is then created
• Rules base is designed and created too
• An inference engine is also designed and created
• The input screen and output format are also designed and created
• The expert system is tested against known conditions and scenarios.
• It is also checked to see if it meets the original specification.
• Experts are interviewed about how effective it is before the expert system goes out on general release.
• Advantages: 
• Consistent answers
• Not time consuming
• Saving money because they do not have to pay for a skilled person
• Disadvantages: 
• Lack common sense
• Errors in knowledge base will lead to wrong decision making
• Expensive to set in the first time

ICT Class Eighth Meeting

Batch Processing Applications, Automatic Stock Control and Online Booking Systems

A. BATCH PROCESSING APPLICATIONS

1. Payroll

• Payroll systems are used to calculate wages and print out pay slips.
• The inputs are: 
• employee details from file
• number of hours worked
• overtime working
• holidays
• The processing done is calculation of: 
• gross pay
• any deductions
• net pay
• The outputs are: 
• printed pay slips
• updating of the employee file
• transfer to Bankers Automated Clearing Service (BACS) if wages paid into a bank account
• The stages of batch processing is shown below:

2. Billing Systems

• Billing systems can be used for electricity bills. 
• The inputs are:
• customer details (address)
• charge per kW (unit) of power
• previous readings
• new readings taken from the electricity meter
• bank account details (if using direct debit)
• The processing done is the calculation of: 
• number of units of electricity used (i.e. new reading minus old reading)
• customer’s cost (i.e. units used times charge per unit)
• monthly payments made (if using direct debit)
• outstanding amount owed or carried over to next bill
• The outputs are: 
• bill showing all the details
• updating of customer file
• production of request for payment if not done through direct debit

B. AUTOMATIC STOCK CONTROL

1. Automatic stock control systems rely on the use of barcodes.A number underneath the barcode usually consists of four parts: country code, manufacturer’s code, product code and a check digit. The check digit is a form of validation which is used to make sure no errors occurred during the reading of the barcode.

2. The check digit can be calculated in various ways. This in one of the examples.

3. Barcodes can be used for: 

• library book systems
• administration systems
• passport and ID card systems
• some burglar alarm systems

C. ONLINE BOOKING SYSTEMS

1. Booking systems are used for transport (flights, trains and buses), cinemas and theatres.

2. Once the customer booked the seat, the seat will no longer be available. Thus, nobody can book that seat again. This system must be done quickly and immediately to prevent double booking. 

3. An e ticket will be printed after the customer has done both the booking and the payment. 

4. This system is now widely used in many cinemas and theatres. 

ICT Class Seventh Meeting

Control Applications and Robotics

A. CONTROL APPLICATIONS

1. Turtle Graphics

• Based on the computer language named 'LOGO'.
• The control movement of a 'turtle' that is being guided by the instructions typed into the computer.
• These graphics are usually used by little children to understand the basic concepts of computer.
• Below is the most common commands used in turtle graphics.

• By understanding these commands, we can control the movements of the 'turtle'. 

2. Applications Using Sensors

• In monitoring and controlling, sensors are used by the computer then the data will be processed. 
• However there are differences between monitoring and controlling. These are the details of their differences: 
• Monitoring
• Computer simply reviews the data from the sensors and updates its files and/or gives a warning signal if the values are outside given parameters.
• No changes to the process are made during monitoring.
• Examples: 
• monitoring a patient’s vital signs in a hospital
1. Sensors read key vital signs
2. The data from the sensors is converted into digital using an ADC.
3. The data is stored in the computer’s memory.
4. The computer compares the data from the sensors with the values stored in its memory.
5. The results are output on a screen in the form of graphs and/or digital read-outs.
6. An alarm is activated if any of the data is outside acceptable parameters.
7. The system continues to monitor the patient until the computer is turned off.
• monitoring a scientific experiment in a laboratory
• a burglar alarm system
• Advantages of monitoring applications: 
• Very efficient since computer can work 24 hours 
• Will not make people waste their time since people can do other things aside from monitoring
• The response by the computer is fast
• The readings tend to be more accurate
• Controlling
• The computer again reviews the data from the sensors, but if the values are outside the given parameters it takes action to try and get the values within acceptable ranges
• It does this by sending signals to devices controlling the process.
• Examples:
• controlling a chemical process
• controlling a nuclear reactor
• controlling a greenhouse environment
• Advantages of controlling applications: 
• The response time if some parameter is out of range is much faster
• This is safer, as some processes are potentially dangerous if they go wrong
• If a process is dangerous, it is better to control it from a distance.

B. Robotics

1. Robots are used in many areas of manufacturing, from heavy work right through to delicate operations.
2. Uses of robotics:

• paint spraying of car bodies
• welding bodywork on cars
•  manufacturing of microchips
• manufacturing electrical goods 
• automatic warehouses.

3. Control of robots can be done in two ways: 

• embedded microprocessors
• linked to a computer system

4. Advantages of robotics: 

• greater consistency as they would make the same product repeatedly 
• higher efficiency since robots can do 24/7 work while humans can't
• higher productivity because robots can do much faster than human
• less expensive in long term

5. Disadvantages of robotics: 

•  may lead to unemployment since it replaces the labor
• robots find it difficult to do unusual tasks

This concludes my ICT class seventh meeting. 

ICT Class Sixth Meeting

Modelling Applications and Types of Processing 

A. MODELLING APPLICATIONS 

1. Tuck Shop

• The table above shows an example of a tuck shop spreadsheet. 
• By using this model, we can know the profit or loss of a shop. 
• This is a very simple model but it shows the principal of using spreadsheets to carry out any type of modelling that can be represented in a mathematical form.

2. Traffic Light Simulation 

• To carry the traffic light simulation correctly, data must be collected first. 
  
• The data that needs to be collected in processing this simulation are: 
• the number of vehicles passing the junction in all directions
• the time of day for the vehicle count
• how many vehicles build up at the junction at different times of the day
• how vehicle movements change at weekends, bank holidays, etc.
• how long it takes a vehicle to clear the junction
• how long it takes the slowest vehicle to pass through the junction
• the movements made by vehicles (e.g. left turns, right turns, filtering, etc.)
• additional environmental factors, such as whether there are pedestrian
• crossings nearby.
• After data is already collected, the designers can carry out the simulation. However, there can be different scenarios happening in the traffic. 
• Here are some examples of those scenarios: 
• vary the timing of the lights and see how the traffic flow is affected
• build up the number of vehicles stopped at part of the junction and then change
• the timing of the lights to see how the traffic flow is affected
• increase or decrease traffic flow in all directions
• how emergency vehicles affect traffic flow at different times of the day.
• This simulation can then be used to optimize the flow of traffic through the junction on an ongoing basis.
• Sensors in the road gather data and count the number of vehicles at the junction.
• This data is sent to a control box or to a computer. It may need to be converted first into a form understood by the computer.
• The gathered data is compared to data stored in the system. The stored data is based on model/simulation predictions which were used to optimize the traffic flow.
• The control box or computer ‘decides’ what action needs to be taken.
• Signals are sent out to the traffic lights to change their timing if necessary.

B. TYPES OF PROCESSING

1. Batch Processing

• In this process, jobs or tasks are first collected in the computer over a period of time. 
• Then, the jobs are loaded into the computer system and processed all together or batched. 
• User interaction is not required once batch processing starts. 
• This process cannot be used if users need the data directly or immediately. 
• Advantages of batch processing:
• Jobs can be processed when the system is not being used 
• Used mainly for billing systems, payroll systems and bank cheques.  

2. Real Time Processing 

• This process is an example of online processing. 
• Different from batch processing, this processing needs to be done immediately. 
• Real time processing is commonly used in the systems for airplane or theatre seat bookings. 
• Another example may include the ATM machine. 

3. Real Time Process Control 

• This process is an example of online processing but differ with real time processing in a few ways. 
• This system usually involves sensors and feedback loops 
• One of the examples of the uses of real time process control is temperature in which it is continually monitored and the input is processed sufficiently quickly to influence the input source.