116 3.1 Explain the following Object Oriented design principles: 3.1.1 Coupling 3.12 Cohesion 3.1.3 Navigation visibility 3.2 Describe whole part relationships in relation to and demonstrate how they are represented in UML class diagrams. Questin 4 Consider the scenario of a car wash business and answer the questions that follow. (10) or the manager to effectively manage the scheduling of cars to be washed and to manage time effic iently, he has requested an IT company to develop a system that will make it possible for car owners to use a mobile app to book for the washing of their cars. When a booking is made the car owner will enter his/h her details including contact nurnbers, enter the vehicle details such as registration number, description, etc. and selected type of washing required. The system will determine and display the available time slcts so that the owner can select a suitable slot. The system als the car wash. The booking details including the amount te be paid are displayed so the owner can o checks the status of the car owner, car owners who are troublesome are barred from select a form of payment. The vehicle owner thet confivs the booking. The manager may select the manage bookings to cancel or reschedule bookings On the last day of the week the system generates reports for manager to view the number of cars washed by each wash bay employees. The system also allows for the accumulation of points every time a car is brought for washing. When a certain number of points is reached the system sends out an SMS to the owner inviting for a free car wash 4.1 List three and describe three types of events. For each even type give an example from the case study above. 4.2 Develop a state machine diagram showing states and transitions for the car object. When a booked car arrives at the car wash it is allocated to a washing bay which is manned by washing personnel and marked as such on the system. When washing is completed the car is then parked at the collection area and set as ready for collection on the system. The owner of the car is notified to make a payment and collect the car so it can be recorded as released from all the ba ys