- Railways, like a lot of industries are becoming increasingly reliant on programmable technology for safety. The development of railway technology is however largely driven through market forces and, given the complexity and cost of developing and certifying safety-related systems, rail industry suppliers tend to accede to the needs of their bigger customers. Consequently the in-built functionality is targeted to specific customer needs, and as these needs can vary considerably between railways, there is often a need for customisation to suit a particular application. However, railway products are constantly evolving largely because of technology obsolescence, but also to enhance through added functionality, whilst sometimes also removing no longer necessary functionality. This paper provides a case study for one such product, namely an axle counter system, which was developed for application on the QR rail network. The first of the systems were brought into service in 1987 and are still in use today. Since then, there have been several evolutions of the product, which progressively saw the removal of functionality and customisation required by QR. The paper describes the application of the axle counter product within QR, the initial development, and what is being done to enable the use of the latest version of the product.