People$$s Wellness Collective is a not$-$for$-$profit, member owned co$-$operative that provides affordable medical and healthcare services to the communities where it operates. People$$s Wellness Collective hosts a number of doctors $($GPs and specialists$)$ and nurses that look after patients. For administrative purposes, People$$s Wellness Collective needs an IT system that processes patient administration records $($not actual medical records$).$ Each patient has a record with his or her name, gender, date of birth, date of first visit, and date of last visit. Patient records are

grouped together under a household. A household has attributes such as name of head of household, telephone number, and address. Each household is also associated with an insurance carrier record, containing name of insurance company, address, billing contact person, and telephone number.

At People$$s Wellness Collective, each medical staff person also has a record that tracks who works with a patient $($doctor$,$ nurse, medical technician$).$ Because the system focuses on patient administration records, only minimal information is kept about each medical staff person, such as name, address, and telephone number. Information is maintained about each office visit, such as date, insurance copay amount $($amount paid by the patient$),$ paid code, and amount actually paid. Each visit is for a single patient, but, of course, a patient will have many office visits in the system. During each visit, more than one medical staff person may be involved by doing a procedure. For example, the medical technician, doctor, and nurse may all be involved on a single visit. In fact, some doctors are specialists in certain medical fields; even multiple doctors may be involved with a patient. For each staff person that does a procedure in a visit combination $($many$-$to$-$many$),$ detailed information is kept about the procedure. This information includes the type of procedure, a description, the copay amount, the total charge, the amount paid, and the amount the insurance company denied.

Another domain that the system will need to keep track of relates to invoicing. There are two types of invoices: invoices to insurance companies and invoices to heads of household. Both types of invoices are fairly similar, listing each visit, the procedures involved, the patient copay amount, and the total due. Obviously, the totals for the insurance company are different from the patient amounts owed. Even though an invoice is a report $($when printed$),$ it also maintains some information such as date sent, total amount, amount already paid, amount due and the total received, date received, and total denied. The latter is relevant because insurance companies do not always pay the full amount they were billed for.

Information about patient and head$-$of$-$household information, will be entered and kept up to date in the system by the receptionist. The receptionist will also keep track of office visits by the patients. Patient information is also entered and maintained by the office business manager. In addition, the business manager maintains the information about the medical staff.

Another responsibility of the business manager is to print the invoices. Patient invoices are printed monthly and sent to the head of household. Insurance invoices are printed weekly. When the invoices are printed, the business manager double$-$checks a few invoices against information in the system to make sure it is being aggregated correctly. When payment is received, s$/$he also enters this information in the system.

Medical staff are responsible for entering information about the medical procedures they perform. The business manager also prints an overdue invoice report that shows heads of household who are behind on their payments. Sometimes doctors like to see a list of the procedures they performed during a week or month, and they can request that report. Provide a brief overview of the purpose of a state machine diagram. Draw a state machine diagram for an insurance invoice class based on this information. Include transition names and be sure to consider all of the possible transitions.