The paper “ Engineering Requirements for Coffee System and Drinks Machine Control System” is a meaningful variant of assignment on engineering. The following UML use case diagram provides an overview of how the proposed drinks machine control system will function. In this scenario, the interaction is between four actors and the system which is also considered an actor. The user initiates the interaction by inputting coins in the vending machine and places their order. Here they specify the drink they want by punching the keypad. A user can cancel their order of a drink before it is dispensed.
Once the system receives the amount from the user, it has to validate that amount and give change if required. In case, the coin box is full, an alert is sent to the service operator through the network for necessary action. If everything is functioning properly, the system prepares the drinks by heating and mixing the required ingredients before serving the customer. Once served, the system cleans the vessel. Use case descriptions ID UC1 Name Deposit coins Description Coffee customer deposits coins to buy a drink Event flow -Deposit coins -include UC2 - Extension points Verify amount Triggers Postcondition -dispense drink ID UC2 Name Chose drink Description Specify drink using keypad Event flow The drink must be available Coin verification complete Extension points Triggers Postcondition ID UC3 Name Get drink code Description Customer types the drunk code in the keypad Precondition Drink code available Event flow -include deposit coins -include coin verification Extension point User cancel order Triggers Choosing a drink Postcondition ID UC4 Name Cancel drink Description Customer cancels the drink Precondition A drink should not be dispensed Event flow Extension point Get drink code Triggers Wrong choice of drink Postcondition ID UC5 Name Download information Description Service operator sends request Precondition System sends alerts Event flow -include authentic operator -chose during to show information -download information Extension point Triggers System alerts Postcondition ID UC6 Name Verify Amount Description System verifies customer amount Precondition Customer has inserted coins Event flow -include deposit coins Extension point Extend alerts Triggers Coins available Postcondition Prepare drinks ID UC7 Name Alerts Description System sends alerts to service operator Precondition Coin box is full Event flow Include verify amount Extension point Extend verify amount Triggers Sensors Postcondition Send engineer ID UC8 Name Heating and mixing Description System heats the water Precondition Customer orders drink Verified amount Event flow Extension point Extend preparing drinks Triggers Recipe available Postcondition Dispense drink ID UC9 Name Prepare drinks Description System prepares drinks Precondition Hot water available Drink recipe available Event flow Water is heated Extension point Heating and mixing Triggers Available drinks Postcondition Dispense drink ID UC10 Name Dispense drinks Description System fills customer cup with order Precondition Drink is prepared Event flow Extension point Extend get drink code Triggers Drink preparation complete Postcondition ID UC11 Name Cleaning vessel Description System cleans dispenser after serving drink Precondition Hot water available Event flow Drinks are dispensed Extension point Triggers Postcondition Heating and mixing ID UC12 Name System testing Description Service engineer tests the system Precondition Alerts sent to operator Event flow Authenticate engineer Extension point Extend verification Triggers Postcondition Coffee system in service Task 2Any system should be verifiable and tested to meet the set goals and objectives.
The proposed coffee system is not an exception. Below is a list of the non-functional requirements that will make its use efficient. Usability- the proposed system should be easy to use for the end user, the engineer and the service operator. Usability of the system can be tested by the ease of dispensing the required drink for first time users of the system. Customers should be able to purchase drinks without any training. The administration of the system should not be complex such that it takes all the time for the administrators and engineers especially when making updates. Performance-the system should serve the users within the shortest time possible.
The time between inserting coins and getting the drink should be very small as this will increase efficiency. Performance can be tested by measuring and determining the time it takes to serve one customer. Resilient- the system should not be crashing easily as this would inconvenience the users and the administrators of the system. System resilience can be tested by recording the number of time it crashes or is out of service within a given week or month. Safety- a good system should be safe and not pose any risk to the users.
The system should adhere to safety regulations and promote a risk free serving environment. Safety can be tested by recording the number of times the system has posed a risk to the users by either blowing up or poring hot beverages on people. Updating-the system should not be comprehensive. A good system should leave enough room for upgrading and updating based on the feedback provided by the users. Therefore, the system should provide more room for updating and comprehensive updates.
This non-functional requirements may be measured and verified by getting customer’ s feedback to determine what is lacking and what needs to be improved in the system. Task 3Design three UML state machine diagrams (also known as statechart diagrams) Water heater sub system sub-system.