Roles, Databases, and Interactions

Roles

Customer
The customer is any person who is using the system to obtain information regarding travel through the system.

Station Manager
The Station Manager is responsible for maintaining either a part or the whole system. This include making up the schedules, managing which tracks are used for which trains, and handling train-related emergancies.

Administrator
The Administrator is responsible for the maintainence and operations of the infrastructure and software used to implement this MetroSub system.

Conductor
The Conductor is responsible for a single train. This includes actually driving the train, as well as handling any problems which occur during normal operation.

Mechanic
The Mechanic is responsible for the routine and extraordinary repairs and upgrades which occur in the subway system.

Sales
The sales person is responsible for the selling of tickets and other customer service functions.

Databases

Schedules
Stores the permanent day-to-day schedule of which trains will run which routes, and what those routes will be.

Inventory
Stores the types and amount of the various items which are required to run a subway system (e.g. copier paper, flurescent lights, railroad ties, etc.).

Billing
Stores the information regarding the various customers (both credit and debit), as well as their account standing.

Status
Stores the current (i.e. real-time) status of each train, station, length of track, etc. in the system.

Maintainence
Stores the work orders currently under-way within the subway system.

Statistics
Stores demographic information (esp. usage information over time).

Topology
Stores the actual vector data which represents the physical connections and locations of immobil items in the subway. This is used to generate the maps used in the subway system.

Credit Card*
This database is accessesed to allow the customer's credit card to be automatically billed at the end of the month for any outstanding balences.

Security*
The Security database is merely a write-only connection to the munciple emergancy services database.

Mass Transit*
This includes any connections to other mass transit system existant within the same munincipality.

* indicates an external database

Database Access Permissions vs. User Role

Sch Inv Bil Sta Mai Sta Top Cre Sec Mas
Cus R - LRW LR - - LR - W RW
Sta LRW LRW - LRW LRW LR LRW - W -
Adm - RW - R RW - R - W -
Con R R - LRW LRW - R - W -
Mec R RW - RW RW - R - W -
Sal R - RW R - - R RW W RW