CMC's scheduling software runs the London Underground on which over 460 trains crisscross each other during peak hours, carrying more than 800 million passengers a year.

The product
Time-table scheduling and signal data generation system
Developing a system for timetabling / operation plan generation, after re-engineering the original system

The client
London Underground Limited
The world's oldest and most complex subway rail network

Over 460 trains during peak hours crisscross each other over an area of 2000 sq km, carrying over 800 million passengers a year. The London Underground is the world's oldest and most complex subway rail network. Naturally, the job of designing its train scheduling system was entrusted to one of the leaders in information technology.

CMC was awarded a contract by London Underground in 1989, to migrate the system and to design and develop a database for its timetabling / operation plan generation software. CMC successfully delivered the CART (Computer Aided Railway Timetabling) system then, and have been giving onsite support to LUL, making necessary changes to the system as and when required.

In 1998, CART was made available to the scheduling department on their Windows PC using Hummingbird's Exceed emulator. The CART software too, was migrated to a more powerful SUN machine. The migration to the new hardware platform was done offshore in Hyderabad. The installation and setting of the Exceed software was done by the onsite team in London. This arrangement made available the usual windows application like MS Word, Excel and PowerPoint to CART users. Previously, users had to go to a different PC to do any other work.

In 2002, LUL took a decision to re-engineer CART and use Oracle as the database. LUL asked CMC to provide various solutions for implementing the new system. CMC recommended using Developer 6i with Oracle and also provided training on Oracle to LUL key staff. As proof of the concept project, CMC developed a highly customised Workflow Management Application (WMA) using Developer 6i and Oracle 8i for the scheduling department. WMA provides automated Task Management, Resource Management and Allocation Function for the Scheduling Department. This software was part of the migration of CART from Ingres to Oracle. WMA was deployed in May 2003 and since then has been used by the scheduling department for generating timetables. CMC was responsible for the user interface, the physical database design and the coding.

After the success of WMA, CMC embarked on the mammoth task of reverse engineering each module of CART, identifying and removing obsolete pieces of code and rewriting the technical documentation. CMC is also responsible for designing a Data Bridge software which migrates user selected timetables from the CART system to the new COS (CART Oracle System) application. CMC used LUL's standard software, System Architect 2000, to create the dataflow and entity relationship diagrams. In the meanwhile, CMC is also responsible for maintaining and enhancing the CART application.

Project
Maintaining the existing CART / WMA application and developing the COS system.

Background

	10 different subway lines
	450 trains running concurrently
	Total geographical area of 2000 sq km

	Time-table for each train
	Input tapes for signal control machines

Technology of the earlier application

	Ingres 6.4
	C, ESQLC and 4GL
	Flat files
	1,50,000 lines of programme code
	Unix shell scripts
	Postscript outputs

Functionality of the earlier system

	Schedule generation
	Platform number generation
	Schedule transformation
	Working time-table preparation
	Signal data generation
	Mileage statistics
	Train registers
	ASCII timetable export (CSV file)

Problems in the earlier system

	Expensive to maintain and operate
	Training was difficult
	Unsupported database

Technical issues

	System had to be reverse-engineered from source code
	Functionality of each module had to be extracted from the source code
	The modules were redesigned completely in a structured manner
	Oracle relational database was selected
	System designed using SSADM methodology
	Developed PLSQL coding standards and GUI design standards
	Extensive testing
	All analysis, design and programme documentation using the system architect

CMC's tasks

	Re-designing the application
	Re-development in a client-server environment
	Creating a friendly user interface
	Removing redundancies in the system
	Providing on-going system support

The new system has transformed the entire time-table compilation process. It is much easier to operate and maintain and can be adapted to provide for the extension of existing lines and the introduction of new ones.