M206 - TMA07 - Question 1

(i) Project III postings

Posting 1

Re Student A's question regarding how to treat the senior faculty staff involved in the RABS scheme. Since they do not appear to have any different roles from the university administrators, I therefore agree that they should be treated as equals with other users of the system.

I agree with Student B's list of classes with the exception of the Rental class. The negotiated statement states "Once the user makes his or her choice, the system will record the fact that the particular bike is rented to the user'. I feel that associating instances of Bike and instances of RegisteredUser will achieve this requirement though the said association without the necessity for a Rental Class.

My revised list of classes follows:

• Class: Administration
• "There is only one instance of this class and it is the orchestrating instance"
• Class: Bike
• "Abstract...
• Class: MTB
• Is-a-kind-of: Bike
• Class: RoadBike
• Is-a-kind-of: Bike
• Class: RegisteredUser
• "Abstract...
• Class: Individual User
• Is-a-kind-of: RegisteredUser
• Class: GroupLeaderUser
• Is-a-kind-of: RegisteredUser
• Class: Reservation

Posting 2

From the negotiated statement

Group registration involves recording the room number, name and period of stay of the responsible group leader along with the number of individuals who comprise the group (there is no need to record who those individuals are). If a resident wishes to rent bikes both as an individual and as a group leader then they must register twice - both as an individual and as a group leader.

At the end of the day, a check is made by the system for any bikes that are still not returned. In each case of a non-returned bike, RABS will mark the user (individual or group leader) as being barred from further rental or reservation and will inform the main booking and billing system of this fact.

This means that if a group member does not return a bike by day end the group leader is barred from group renting bikes for the remainder of the stay. Since the system does not record who is in a group, the offending group member can still rent or reserve a bike as an individual thus incurring no penalty. Is this right and is there any way of dealing with this problem?

I agree with Student B's list of associations which follows:

Class	Name	Multiplicity	Class
Administration	Bikes	one to many	Bike
Administration	RegisteredUsers	one to many	RegisteredUser
IndividualUser	Has-made	one to one*	Reservation
Reservation	For-A	one to one	RoadBike
RegisteredUser	Is-Rented-To	one to many	Bike

*There is some suggestion in the Statement that this may be one to many where it says '...if a resident wishes to reserve a bike for several days, then he or she must reserve the bike on each successive day' This might mean multiple reservations let me know what you all think.

I would agree that where the Statement says' if a resident... does indeed call for a one to many since it is clearly stated that a bike may only be reserved for a day at a time.

Posting 3

I agree with Student C and Student D that it is difficult to contribute new ideas or thoughts to this conference at this late stage.

• RABS System Class Association Diagram
  
• Class: RABSystern
  "There is only one instance of this class and it is the orchestrating instance."
• Responsibilities:
  Keeps track of Bike instances corresponding to identification numbers.
  Keeps track of RegisteredUser instances corresponding to room number and name.
• Class: Bike
  "Abstract... "
• Responsibilities:
  Records the unique bike identification number.
• Class: MTB
  Is-a-kind-of: Bike
• Responsibilities:
  Records the unique police code number.
• Class: RoadBike
  Is-a-kind-of: Bike
• Responsibilities:
  Records the bike size and equipment fitted
• Class: RegisteredUser
  "Abstract...
• Responsibilities:
  Records the user's room number, name, period of stay and barred status.
• Class: GroupLeaderUser
  Is-a-kind-of: RegisteredUser
• Responsibilities:
  Records the number of Users in a group lead by a GroupLeader.
• Class: IndividualUser
  Is-a-kind-of: RegisteredUser
• Responsibilities:
  Maintains the user's Organisation.
• Class: Reservation
  Responsibilities:
  Records the reservation date
  Records the intended rental date.
  Records the reservation status
  Keeps track of Reservation instances the user has made corresponding to the date of intended rental.
  Keeps track of Bike instances corresponding to bike identification number of reserved bike.

Question 2