Vending Machine Visual Basic Problem -- 2

Program Requirement A program is required to simulate a snack vending machine. The snack machine will vend crisps at 55p, chocolate biscuits at 50p, nuts at 55p and cereal bars at 65p. The program will run in a continuous loop. At points during the program, a menu will be displayed from which the user can either select a snack, or choose to checkout all snacks selected so far. If a snack has been selected the program will display the snack selected and ask the user to select how many they would like, then it will return to the menu. An entry of 0 will cause that selection to be ignored. The menu will always show all snacks that have been selected so far, with the quantities and the total amount to pay. The user can continue to select snacks until they are ready to buy. When the user chooses to checkout their purchases, they will be shown a list of the items and quantities they have chosen, a total amount to pay and a request to enter money. Money entry is simulated by the user entering the value of each coin. The machine will accept £10 notes, £5 notes, £2 coins, £1 coins, 50 pence, 20 pence, 10 pence and 5 pence. It must reject entries of all other monetary values except 0 which means that the user would like to cancel the purchase. As soon as enough money has been entered the snacks will be dispensed, one at a time (shown by displaying messages on the screen). If too much money was entered, change will be given. To maintain the correct working of the machine, the stock of each snack must be continually monitored and occasionally refilled. There will be 50 of each snack loaded in the machine at the beginning of the program. If a user chooses to buy more of a particular snack than is currently present in the machine, the program must tell them and allow them to reselect. The machine is refilled by selecting 0 at the main menu (this option should not be displayed). When 0 is selected the user is asked to enter how many of each snack they are loading into the machine (the total of the amount loaded and the amount still in the machine must not exceed 50). Your Tasks Task 1 Produce a program specification to meet the given requirements. Your specification must include: • A definition of input, processing and output requirements • A description of how your program specification meets and/or deviates from the given requirements. • An explanation of how you have ensured the user’s needs will be met. Task 2 Produce a program design to meet your program specification. You must include the design of: • Inputs • Outputs • Processes (using appropriate process description methods) • Data structures • File structures and file organisation. Task 3 Produce a working program to realise your design. Your program must include at least one data structure (e.g. to hold details of the quantity of each snack in the machine or a structure to hold details of all the snacks chosen by the user up to checking out) and must use all data types, control structures and operators listed in the programming section of the unit specification (page 98 and 99). Your program listing must be annotated with appropriate comments. You must submit a program listing and screen dumps to illustrate the operation of your program. Task 4 Produce a test plan and a record of testing. Your plan must cover: • All input data validation (including valid, invalid and boundary data) • All user operations • All paths through the processes.