Question $1(2\mathrm{.}5$ pts$)$

You own a small resort of summer cottages and ask a local software developer to create a reservation system you can use to manage bookings. Before accepting the software you test it thoroughly.

You have $20$ cottages that you refer to as #$1,$ #$2...$ #$20$ and operate the resort for $12$ weeks over the months of June, July and August.

Weekly rental for each cottage is $$1000$ per week. The rental period is from noon on a Sunday to noon on the following Saturday. You clean and prepare for the next customer each Saturday afternoon and Sunday morning.

Assume all customers stay one week.

For each of the $20$ cottages and each of the $12$ weeks, the use cases may occur.

Big hint: the states of a reservation are shown in bold.

Use cases:

$$ To start, the reservation system marks all cottages as available for all weeks.

$$ Customers may contact you by phone or email to ask about availability, prices and the like.

o The system lets you add information about potential customers to your mailing list.

$$ A customer contacts you by phone or email to reserve a cottage or a certain week.

o If the requested cottage and$/$or week are not available, you suggest alternatives.

o When you and the customer agree on a cottage and week, and the system lets you indicate that the cottage is reserved.

$$ Upon reserving, the customer must send you a deposit of $$250$ if the arrival date is more three weeks ahead.

o If the deposit arrives within seven days, the cottage is marked as booked.

o If the deposit does not arrive within seven days, the system cancels the reservation and the cottage becomes available for rental to another customer.

$$ Full payment is due three weeks before the arrival date. That means a customer who reserved with a deposit of $$250$ must pay the balance of $$750$ at least $21$ days before arriving. A customer who books late $($less than $21$ days before arriving$)$ must pay the full amount of $$1000$ within seven days of reserving.

o When the balance of rental payment arrives, the system lets you mark the cottage as rented.

o If the balance of rental payment does not arrive $21$ days before the arrival date:

$$ The system cancels the booking and the cottage becomes available.

$$ You keep the deposit $($if the customer paid it$).$

$$ A customer may cancel a reservation or booking.

o The system lets you indicate the cottage is available again.

o If the customer cancels more than $3$ months $(90$ days$)$ before the arrival date, you return all money paid $-$ deposit and balance of payment $($if paid$).$

o If the customer cancels between $3$ months and $3$ weeks of the arrival date $(89-21$ days$)$ you keep the deposit and return the balance of payment $($if paid$).$

o If the customer cancels within $20$ days of the arrival date, you keep all money paid.

$$ On the arrival date, the cottage becomes occupied.

o If the customer does not turn up$,$ you honour the booking anyway, in case the customer arrives late.

Q$1(2\mathrm{.}5$ pts$)$ Draw a state transition diagram for a reservation or booking record.

Consider that the diagram is the same for all $20$ cottages and all $12$ weeks, but shows the state of a booking for one cottage and one week.