railway route planning in australia

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Railwayroute planning in Australia by ALEX GOODALL ~ ile many companies are in- vestigating the area of expert systems in the hope that these can help solve their problems, little is heard about such systems, outside the test or demonstration area, that do anything useful for commercial users. It seems as if most of the products and tools are confined to the research and academic com- munity and regarded as futuristic dreams by many commercial organiz- ations. There are signs, however, that ex- pert systems technology has reached the stage where it is becoming com- mercially attractive. Thomas Cook is the world’s largest travel agency, with a long record of applying technology to the leisure business. So it is not surprising that one of the UK’s first commercial expert systems has been installed at its Abstract: A software conrpany and major travel agent have jointly developed an expertiinfonnation retrieval system. The system maps out itineriesthrough Austrcilia’s complex rail network. Queries on this subject had previously always been passed to the human expert. Keywords: data processing, software techniques, expert systems,information retrieval. Alex Goodall is managing director of Expert Systems International Ltd. head office in Peterborough. The system, designed and built by Expert Systems International Limited of Ox- ford, in association with Thomas Cook, performs the task of itinerary planning for the Railways of Australia and is currently in daily use running on an IBM PC/AT. An expert system has the ability to mimic to a certain extent a human expert in a consultative role. As such it is seen by Thomas Cook as an area of tremendous potential, since a key element in its service to customers is the ability to select information and make correct decisions quickly. In addition, the company employs many staff with key skills and know- ledge, built up through long experi- ence in the travel industry. The ex- pert system is seen as an opportunity to collate this knowledge and make it available to less experienced staff. Finding a suitable pilot project Having decided to move into the field of expert systems, the problem was to find an application which would be suitable for a pilot project. While it considered that the system would be to a certain extent experimental and educational, Thomas Cook was also determined that they system should work in an area where positive bene- fits would be seen at the end of the day. 136 00I1-6g.$X:86~03013~03$03.00 0 1986 Butterworth Kr CoiPublishers~ Ltd data processing After careful consideration, a pro- ject to build an itinerary planner for the Railways of Australia network was selected. The choice was based on a number of factors. First, the problem was of a suitable size. Thomas Cook deals with all inquiries and bookings concerning the Railways of Australia, both from its own and other travel agents in the UK. The volume of transactions was large enough for Thomas Cook to have dedicated a number of staff to the task, but not so great as to overburden the project with more traditional data processing problems. Second, the information about the railway network of Austraiia is quite complicated. The department con- cerned used to spend much time thumbing through voluminous time- tables to provide information in re- sponse to telephone inquiries, which were frequently referred to the department’s main expert in the Aus- tralian railway system. The most ex- tensive knowledge was therefore iso- lated in the experience of a single employee of Thomas Cook. This reli- ance on a single expert was a situation that the system sought to ease, but it was a benefit for the project in that there was an identifiable expert avail- able for the knowledge acquisition process. Third, such an expert system would have potential for further applications. The system could be relevant to any network of scheduled traffic, with a minimum of redesign- ing and translation work, provided that the information could be repre- sented at timetable level. The expert system To design and help develop the appli- cation, Thomas Cook appointed Ex- pert Systems International, a leading British company in the field of expert computer software. The company is a major centre of implementation for PROLOG, the most favoured artificial intelligence language in Europe and

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Page 1: Railway route planning in Australia

Railway route planning in Australia by ALEX GOODALL

~

ile many companies are in-

vestigating the area of expert systems in the hope that

these can help solve their problems, little is heard about such systems, outside the test or demonstration area, that do anything useful for commercial users. It seems as if most of the products and tools are confined to the research and academic com- munity and regarded as futuristic dreams by many commercial organiz- ations.

There are signs, however, that ex- pert systems technology has reached the stage where it is becoming com- mercially attractive.

Thomas Cook is the world’s largest travel agency, with a long record of applying technology to the leisure business. So it is not surprising that

one of the UK’s first commercial expert systems has been installed at its

Abstract: A software conrpany and major travel agent have jointly developed an expertiinfonnation retrieval system. The system maps out itineries through Austrcilia’s complex rail network. Queries on this subject had previously always been passed to the human expert.

Keywords: data processing, software techniques, expert systems, information retrieval.

Alex Goodall is managing director of Expert Systems International Ltd.

head office in Peterborough. The

system, designed and built by Expert Systems International Limited of Ox- ford, in association with Thomas Cook, performs the task of itinerary planning for the Railways of Australia

and is currently in daily use running on an IBM PC/AT.

An expert system has the ability to mimic to a certain extent a human expert in a consultative role. As such

it is seen by Thomas Cook as an area of tremendous potential, since a key element in its service to customers is

the ability to select information and make correct decisions quickly.

In addition, the company employs many staff with key skills and know- ledge, built up through long experi- ence in the travel industry. The ex-

pert system is seen as an opportunity to collate this knowledge and make it available to less experienced staff.

Finding a suitable pilot project

Having decided to move into the field

of expert systems, the problem was to find an application which would be suitable for a pilot project. While it considered that the system would be to a certain extent experimental and

educational, Thomas Cook was also determined that they system should work in an area where positive bene- fits would be seen at the end of the day.

136 00I1-6g.$X:86~03013~03$03.00 0 1986 Butterworth Kr CoiPublishers~ Ltd data processing

After careful consideration, a pro- ject to build an itinerary planner for the Railways of Australia network was selected. The choice was based on a

number of factors. First, the problem was of a suitable size. Thomas Cook deals with all inquiries and bookings concerning the Railways of Australia, both from its own and other travel

agents in the UK. The volume of transactions was large enough for Thomas Cook to have dedicated a number of staff to the task, but not so great as to overburden the project with more traditional data processing problems.

Second, the information about the railway network of Austraiia is quite

complicated. The department con- cerned used to spend much time thumbing through voluminous time- tables to provide information in re- sponse to telephone inquiries, which were frequently referred to the department’s main expert in the Aus-

tralian railway system. The most ex- tensive knowledge was therefore iso- lated in the experience of a single

employee of Thomas Cook. This reli- ance on a single expert was a situation that the system sought to ease, but it was a benefit for the project in that there was an identifiable expert avail- able for the knowledge acquisition process.

Third, such an expert system would have potential for further applications. The system could be relevant to any network of scheduled traffic, with a minimum of redesign- ing and translation work, provided that the information could be repre-

sented at timetable level.

The expert system

To design and help develop the appli- cation, Thomas Cook appointed Ex- pert Systems International, a leading British company in the field of expert computer software. The company is a major centre of implementation for PROLOG, the most favoured artificial intelligence language in Europe and

Page 2: Railway route planning in Australia

systems

Figure 1. 7’he Australia rail travel plamer

Japan, and supplies development tools as well as consultancy, design and implementation resources and training facilities.

The prime consideration was ease of use. For this reason it was decided to dispense with the normal keyboard and communicate instead by means of a light pen interface.

Every query referred to the depart- ment prompts a coloured map of Australia on the screen (see Figure l), which shows the railway system in diagrammatic form. Routes are plan- ned by simply touching the light pen on the points of departure and arrival. Some 300 towns all over Australia are catered for by the system and, for

scheduling the journeys, the dates are chosen from a calendar painted elec- tronically on the screen.

Thomas Cook’s new system is a

hybrid expert system and information retrieval system. The expert know- ledge is represented as knowledge rules to guide the system through the railways network of Australia. The

rules were derived from the analysis of interviews between Expert Systems International and Thomas Cook, and from an analysis of the network itself. It includes all the ‘shortcuts’ known to the expert as a result of his experience.

During its searching process, the expert system attempts to copy the methods built up by Thomas Cook’s expert, and makes available inform-

ation that does not appear in the official timetables; information such as the fact that passengers cannot leave the train without a pass at the station which serves the Woomera rocket range.

The knowledge is not merely con- fined to timetable information, but also includes a wealth of other perti- nent information such as local topo- graphy and rolling stock. These are essential features in the construction of high-quality itineraries to meet many and varied customer require- ments.

The system uses an intelligent mul-

tilevel planning technique, and the main emphasis was placed upon plan- ning a route across the timetables. It was realised from the outset of the

development that the timetables themselves represented a great deal of knowledge about the structure of the railway network.

The planning function operates in three phases. The first phase plans the sequence of timetables to be used, assuming certain constraints which

may need to be corrected by the second phase, whose task is to find a physical route from A to B. For example, the first phase treats time- tables as discrete units, and so inserts a stop for each change of- timetable; the second phase will remove such a stop if there is a connecting service, and may add a stop if it is necessary to use a branch line within a timetable.

The third phase schedules the trains across the route, taking account of any time required for stop-offs and optimizing journeys where there is an option.

~0128 no 3 april 1986 137

Page 3: Railway route planning in Australia

Where no times have been specified on the original screen, the planner performs the first two phases and omits the third, to report back on the route only. The schedules can be added and amended manually at a later stage. Alternatively the system

has the facility to store the inform- ation derived from a consultation at any point. This can be retrieved at a

future date should the customer come back with additional information. Printouts of the route planning, in the same format as the screen, are also handled by the system.

For the requirements of Thomas

Cook, the supplementary information about rolling stock and terrain was almost of equal importance as the actual ability to plan schedules. The information, for example, that a par- ticular route would involve a journey across the Nullarbor Plain in a railway

carriage without air-conditioning would probably decide the prospect- ive passenger to request an alternative route from the system.

An information retrieval system

supplies an index to all these snippets of information, and generates text regarding the route which can be called up on the screen simultaneous- ly with the timetables. Ready access to such information is also invaluable for teaching company employees.

Development

The greater part of the elapsed time needed to develop the system was at

the consultative stage. Taped inter- views and test cases over a period of several months were necessary to generate the detailed specification and

design of the system. Thereafter the implementation of the program, writ- ten entirely in Expert Systems Inter- national PROLOG-2, was completed in about six months.

PROLOG-2 is an implementation of the AI language PROLOG. Several of its features were of considerable im- portance for the Thomas Cook pro- ject. Flexible I/O mechanisms and the

138

interface to the 8086 ASSEMBLER allowed the use of the light pen. Window management facilities allow- ed the map of Australia, the calendar,

the itinerary, the information system and other features to be displayed in

coloured windows as and when need- ed. A virtual memory mechanism allowed the complete information sy- stem to be implemented within

PROLOG’s own database. Finally, the compiler could compile the very com- plex search algorithms and the system thus run at an acceptable speed.

PROLOG-2 has certain features that

ease the burden of project develop- ment. Notable amongst these are the debugger and the database editor, both of which are window-based and so do not interfere with the applica- tion I/O.

The ability to use modules further assists the programmer by allowing

the program to be developed in separ- ate modules which are transparent to the user at run time. This is essential for the development of a program, such as the Thomas Cook system, the

code of which occupies nearly 400 kbyte. The benefits are realised par- ticularly in the areas of debugging and efficiency of space usage.

Thomas Cook sees its Railways of Australia system as the first of a series which will make the best possible use of its immense wealth of knowledge

about the travel industry. ‘The pilot system is teaching us a great deal about the practicalities of making effective use of computers,’ com- ments John Birkle, Thomas Cook’s director of Information Services. ‘We are convinced of the potential of these techniques to the company.’

Thomas Cook’s accumulation of vast quantities of knowledge of every aspect of the travel scene from its long years of experience in the travel in-

dustry, can now be captured, stored, and made easily available to all its staff and customers both now and for the future. 0

Expert Systems International Ltd, 9 West Way, Oxford OX2 OJB, UK.

Industry clubs form UK. ‘Clubs’ for expert systems in the Institute for Transport Studies al various industries are now being set the University of Leeds. Valued al up under the Alvey awareness pro- &250000, the project is scheduled fol gramme. The financial contribution completion by June 1987. Thorna> made by member companies is Cook has already completed a project matched by Alvey to provide funding in association with Expert System:

for the development of expert systems International on Australian rail trave. appropriate to that industry. enquiries.

One of the latest clubs to be set up Logica has been appointed to deve. is for the travel and transport in- lop two expert systems for Aries, the ;lustry. Members include Thomas insurance industry club. The first will Cook, American Express, British Air- cover commercial risk assessment oj ways and Sealink, who will be work- warehouse fires and the second will ing together with software house Soft- assist in equity selection for invest- ware Sciences to develop expert sys- ment decisions. The club now has 21 terns for package tour retailing and members, of which 15 are from insur- public transport enquiries. Other ante companies, two are consulting organizations involved in the projects actuaries and four are academic mem- are consultants Wooton Jeffreys and bers.

data processing