The increased use of electronic systems in rolling stock and rail infrastructure undoubtedly improves operational efficiency and safety for the rail operator as well as enhancing the passenger experience. For the rail engineer, however, these electronic systems come with the added challenge of managing obsolescence. Writes Stuart Broadbent
Most component and equipment manufacturers are focussed on their next-generation products and on emerging technologies. This reliance on research and development to provide new revenue streams means that today’s hot new products quickly become commodity and then legacy parts as the manufacturers follow timescales which are driven by fast- moving consumer markets.
Consider the mobile phone industry for example. Mobile-phone users will expect to upgrade their handsets every 18 to 24 months, whereas the planned lifecycle for rolling stock usually stretches to 30 or 40 years.
There is also a significant difference in the volume of units shipped to the consumer and rail industries. Analysts predict that global shipments of mobile handsets will reach 2.5 billion units in 2014. Compare that to the amount of components used in rolling stock, signals, rail infrastructure and passenger information systems and the difference in the production volumes of the two sectors becomes apparent.
The disparity in the expected operational lifetimes and the production volumes means that the focus for most manufacturers will be on the high-tech, high-volume markets rather than legacy, low- volume parts.
The expected lifetime of software also falls short of the life expectancy in the rail industry. Microsoft withdrew support and automatic upgrades for Windows 1998 after just 8 years and ceased support for Windows XP after 12 years.
As Figure 1 shows, the challenge facing rail engineers is to ensure the continued operation of electronic systems far past the point at which the manufacturers no longer produce or support the components within them.
Functional or technical
The types of obsolescence which need to be managed can be described as either technical or functional. In technical obsolescence, the correct operation of the equipment cannot be guaranteed because spare parts or technical support is no longer available from the manufacturer. Examples of technical obsolescence occur when a component manufacturer withdraws a legacy part in favour of one built on a newer technology, or when an industry-standard format evolves into a different footprint or data transmission moves to a different protocol.
In addition to the obsolescence of electronic components, the rail engineer may also have to consider the obsolescence of materials, such as asbestos, or changes in production tools and even ![42907 [online]](http://railengineer.uk/wp-content/uploads/42907-online.jpg)
workforce skills. As older employees retire, the younger recruits may not have been trained on the legacy systems and technologies which are still operating successfully throughout the rail industry.
Functional obsolescence, on the other hand, occurs when the equipment cannot be adapted to meet new standards or regulations for issues such as quality of service and efficiency. Examples  of functional obsolescence include updated regulations for People of Reduced Mobility (PRM), increased use of the radio network resulting in limitations in capacity, or the lower processing power of a legacy computer being unable to support greater demand for sensor inputs or system intelligence.
Managing obsolescence
Whilst obsolescence will remain a daily reality for rail engineers, the risk, impact and cost of obsolescence can and should be mitigated if rail operators and asset owners are to recoup the investment in new equipment and systems. Obsolescence management falls into two categories: reactive management which occurs after an unplanned obsolescence event, and proactive management which aims to predict future obsolescence events and plans strategies to reduce the impact if and when each event occurs.
Reactive management techniques vary widely in both risk and cost. The lowest risk/cost scenario is to use existing inventory or to take advantage of a Last Time Buy (LTB) from the original supplier. If neither of these options is available, purchasing stock from the grey market can be a relatively low-cost option but will inherently increase the risk of buying components which are counterfeit or which have a higher failure rate due to incorrect storage conditions.
Finding an alternative component with the appropriate fit, form and function certainly minimises risk but could also incur the cost of a minor re-design. If none of these options is available, then a relatively high-cost complete re-design or reverse engineering may have to be considered.
A coordinated obsolescence management plan is essential for proactive management. It is also important to create a business-wide culture of obsolescence awareness, particularly in the R&D, engineering, maintenance and purchasing departments.
Proactive obsolescence management should start during the initial stages of product design. Here, the risk of obsolescence can be mitigated by making technology as transparent as possible and by undertaking technology assessments and risk-mapping. Figure 2 shows a typical risk assessment map. Anticipating and planning for upgrades and considering the road- map for each technology are also crucial.
When the product is in service, obsolescence should be monitored at component, product and system level. This is achieved by periodically reviewing the market for emerging technologies and generating a watch list of critical parts.
Sharing information and best practice
Membership of an organisation such as the Component Obsolescence Group provides opportunities to network with people from other companies and industries and to share information about best practice in both obsolescence management and counterfeit avoidance.
The quarterly COG meetings provide a mix of formal presentations and informal events at which obsolescence engineers, buyers and solution providers can exchange ideas on key issues such as REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), conflict minerals and counterfeiting. The meetings also provide access to the latest tools and systems developed to reduce the administrative costs of obsolescence monitoring and management.
Alstom Transport has set up an obsolescence management service as a central function to support all of its businesses in rolling stock, signalling and infrastructure, and the associated service business – and Alstom monitors the obsolescence status of more than 75,000 components. Obsolescence services, including audits, monitoring and solutions, are offered to customers for both Alstom and non-Alstom equipment.
As an example, Alstom is currently developing a GTO gate drive for a major customer to replace a 20 year old product for which electronic components are no longer available. The new product uses Alstom’s original design knowledge combined with the latest technology to deliver a more reliable product.
A reactive obsolescence management strategy is appropriate for low risk sub-systems such as bogies, but a proactive Obsolescence Management Plan is needed to protect the most critical and vulnerable systems against the inevitable changes in technologies and software.
Effective obsolescence management also helps rail engineers to ensure that, throughout the rail industry, the operational lifetime of equipment can be extended far beyond the timescales supported by component manufacturers and software suppliers. So, despite the increasingly throw-away culture of consumer markets, the rail industry should still be able to measure the operational lifetime of its equipment in decades, rather than just years.
Stuart Broadbent is obsolescence director of Alstom Transport and member of the Component Obsolescence Group (COG)Â
