Case Studies

Train Operators Boosts Operational Efficiency and Passenger Service


  • More than doubling of Class 455 Fleet reliability from 6000 miles per failure to 17,000 miles per failure
  • A reduction of 63% in delays, and 66% in cancellations
  • Improved passenger service
  • A saving of £1.1M per year in franchise fines
  • > 50% reduction in depot man-hours required to maintain doors

Award winning TAPAS (Train Automatic Performance Analysis System) more than doubles the reliability of Class 455 fleet and improves operational efficiency to deliver a 63% reduction in delays and a 66% reduction in cancellations.

Business Background and Challenge

Southern run an extensive set of train services between London and the South coast including the Gatwick Express. The business carries around 150 million passengers a year, manages 159 stations and a fleet of nearly 300 new and refurbished trains, 7 days a week and up to 24 hours a day.

Simon Green, Chief Engineer at Southern, explains, “As a train operator we are always looking for innovative ways to improve our service. One of the main impacts on passenger performance is obviously the reliability and efficiency of our trains.”

In particular, Southern’s 46 Class 455 rolling stock units were experiencing reliability and operational issues resulting in 56 cancellations and 2,300 delay minutes in every four week period. So, in partnership with HSBC Rail, Southern embarked on an improvement program with an initial focus on the Class 455 fleet.

When the installation of “black box” recorders was made mandatory for all trains, Southern saw the opportunity to extend the data being collected beyond the minimum required for safety to an enhanced set that would allow them to monitor the behaviour of critical components, as well as track train movements using GPS.

Simon continues, “Our initial focus was increased reliability. We wanted to minimise costly inservice failures by monitoring asset condition and scheduling appropriate preventative maintenance. However, we also wanted a way of profiling train stopping patterns and journey times in order to improve overall efficiency.”

Southern realised from the outset that it did not have the in-house expertise to design and deliver the complex data analysis framework required to turn the raw data from multiple trains on multiple journeys into information it could use to improve maintenance regimes and reduce train stoppages and delays.

Simon adds, “We were also keen to engage with a partner that could provide an objective and innovative approach to interpreting the data. Tessella fitted the bill perfectly. They had the requisite software engineering capability, but more importantly proven expertise in the analysis and modelling of large volumes of complex data”.

The Solution

Tessella worked in close partnership with Southern and HSBC Rail to analyse the system requirements and produce a specification. Because of the difficulty in defining exactly which performance information TAPAS (Train Automatic Performance and Analysis System) should be reporting, an application framework was specified that would allow the Southern engineers to develop and refine the system over time as behaviour patterns were captured and re-evaluated.

Simon continues, “I was impressed by the requirements gathering techniques Tessella used. They were absolutely vital in getting this highly abstracted problem into a form we could all understand and agree to.”

Working closely with Southern’s engineers, Tessella built and refined TAPAS. Phase one of the programme focused on improving train reliability. Using a graphical user interface Southern were able to identify potential failures before they happened, reducing routine maintenance and preventing repeat failures. This translated into increased reliability and less time spent in maintenance, which ultimately benefited Southern’s passengers.

The Benefits

Simon is delighted with the results. “Within a year of the system going live, we were able to exceed our original target of doubling the reliability of the Class 455 Fleet. We have also been able to reduce delay minutes caused by congestion, unnecessary stoppages and reduced traction due to track condition.”

TAPAS has also gone on to win several prestigious industry awards for the innovative way it is able to extend asset life, cut in-service failure, boost efficiency and improve passenger service.

Overall it has led to a 63% reduction in delays and a 66% reduction in cancellations which equates to a £1.1M per year saving for the business in franchise fines. The combined benefits more than cover the investment in the system.

The Future

Following this early success, Southern are looking to extend the TAPAS framework further to reduce the energy consumption of their trains. The aim is to operate a greener, more energy efficient service by maximising the time run at optimum speeds and minimising acceleration and deceleration time caused by unnecessary stoppages. The announcement that Southern’s rail franchise has been renewed to 2015 means that they are ideally placed to maximise the benefits from this innovative system.

Simon concludes, “Tessella have brought more to this project than just raw software design and development capability. Their experience in data analysis and complex systems modelling really complemented our detailed rail engineering experience. Together we have built an asset condition and operational management system that has met its aims in a more comprehensive and innovative way than we could ever have envisioned at the outset.”