output from CASSM stylesheet v1.1 created Dec 2003

CASSM model of: London Underground Ticket Machines

Notes

Relationships
Name Actor Type Acted_on Notes
rel0 Ticket vending machine.Machine type device_constraint Ticket vending machine.Payment method
rel1 Ticket.Ticket type affects Ticket.Period of validity
rel2 Ticket.Period of validity affects Journey.Price
rel3 Ticket.Time of issue affects Ticket.Price
rel4 Ticket.Traveller age status affects Ticket.Price
rel5 Line.Name maps_onto Line.Colour
rel6 Zone consists_of Zone.Stations enclosed
rel7 Journey.Time of travel affects Journey.Price
rel8 Journey.Zones crossed affects Journey.Price
Entities and Attributes
Relns: actor in upright, acted-on in italics.
Name Create/set Delete/change Relns.
User Interface System
Notes
Journey hard hard
present difficult present
Apart from Single or Return journeys to individual zones, specifying the end and start of a journey (even from the same station as where purchased) is not easy. Travelcard journeys can be extended with the Single Zone Extension ticket (and now with pre-paid Oyster cards).
Day of travel easy cant
present difficult present
Weekday, weekend, period. Once purchased, cannot be changed.
Destination station hard cant
present difficult present
The FFM does not allow selection of particular stations, and doing so on the MFM is a lengthier process than zone destinations
Destination zone easy cant
difficult present present
It is much easier to select a destination zone than a particular station, and at offpeak times the MFM will sell a travalcard in place of a retrun, when it is the same price or less. But zone maps are often some distance from the machines.
Line(s) fixed fixed
present absent absent
Lines used on a journey are essential for navigation, but play no part in ticketing
Means of travel fixed fixed
present difficult present
Underground train, overground train, DLR, bus, tram. Travelcards allow all-means travel.
Price fixed fixed rel2 rel7 rel8
present difficult present
The price of a journey is not necessarily the same as that of the ticket (e.g. for returns and travelcards). Prices per journey decrease substantially with travelcards on increased usage.
Source station fixed indirect
present absent present
The source station does not appear on either machine interface
Source zone fixed indirect
difficult absent present
Nor does the source zone, even though knowing which zones will be crossed on one's journey is and important part of both machine usage.
Time of travel hard cant rel7
present difficult present
The transition from peak to off-peak pricing is not shown on either machine interface
Zones crossed hard cant rel8
difficult absent present
Determining the number of zones crossed for a particular journey is difficult, and not shown on the machine interfaces, for any particular journey
Line fixed fixed
present present present
The lines on the 'tube map' play little part in ticketing or ticket pricing
Colour fixed fixed rel5
present absent absent
Line colours do not even appear in Stations or on trains, for the most part
Name fixed fixed rel5
present absent absent
Though essential for navigation, the names of tube lines do not appear on the TVM interfaces
Purchaser easy easy
present present present
E.g. child tickets may be purchased by an adult
Age fixed easy
present present present
It is easy for an Adult to purchase a Child ticket. Family tickets are much cheaper than combinations of Adult and Child tickets
Station fixed fixed
present present present
Many 'underground' stations are wholly above ground
Ticket fixed fixed
present present present
Tickets can be purchases at time of travel, or (for Travelcards) in advance. Travelcard usage is time of day dependent
Date of issue fixed fixed
present difficult present
Date and time of issue is normally the same as purchase
Payment method fixed fixed
present difficult present
Counter, ticket machine, internet.
Period of validity fixed cant rel2 rel1
present difficult present
Period of validity cannot be changed, e.g. by extending a weekly ticket for one day
Price fixed fixed rel3 rel4
present present present
Though cheaper deals can be obtained, e.g. by waiting until 9.30 am
Ticket type fixed cant rel1
present difficult present
The range of ticke types is complex and extensive, and not at all obvious from the machine interfaces. Some tickets types (e.g. Family cards) are 'buried' several interface layers deep.
Time of issue fixed fixed rel3
present difficult present
Traveller age status fixed fixed rel4
present difficult present
Traveller age (Infant, Child, Young Person, Student, OAP, Adult) can affect price
Ticket vending machine bySys bySys
present present present
Machine type bySys bySys rel0
difficult present present
There are three types of machine: FFM (Few Fare Machine), MFM (Multi-Fare Machine) and QB (Queue-Buster). Choice of which machine to use under which circumstances (e.g. stations/zones served, payment methods accepted) is not a trivial issue.
Open/closed status fixed cant
present difficult present
Open/closed status is also hard to discern, and the user has no influence over it.
Payment method fixed fixed rel0
present difficult present
The particular payment methods which any machine accepts is not easy to discern. (FFM is coins only; MFM is coins, notes or cards; QB is cards only)
Payment status fixed cant
present difficult present
Payment status (change availability, notes acceptance, cards acceptance) is not easy to discern while at the machine (because above the user's head), and cannot be set or changed by the user.
Traveller easy easy
present absent present
The traveller may not be the same person as the purchaser (e.g. for family tickets). Underground tickets are not transferrable (even though weekly and longer season tickets require photo id).
(Dis)ability cant cant
present absent absent
The London Underground is accessible to wheelchair users only at a few older stations and on the Jubilee Line Extension.
Age of Traveller easy easy
present difficult present
There are insufficient checks on Adult/Child age status; Child tickets are less than half that of Adult tickets.
Zone fixed fixed rel6
difficult difficult present
Ticket pricing is heavily dependent on Zone boundaries, which have only loose correspondence to geography. Travelcards allow unlimited travel within specified zones.
Name fixed fixed
present present present
1 to 6 and (for Metropolitan Line) A to D
Stations enclosed fixed fixed rel6
present absent present
The zone in which destination stations fall is not shown on either machine interface (but may be on a worn and small paper map on the MFM casing). It is only recently that tube maps showed zone boundaries, and larger maps in stations may be some distance from the machines.