Since propulsion software is not prepared for later modification and differs between vehicles, the required changes can only be realised by or in co-operation with the software engineers having programmed it in the first place. Many times this turns out to be a barrier for two reasons: Usually, software engineers who developed a particular solution are not always available. A software engineer not familiar with the particular train software would need too much time to understand the software in order to change it. Best chances of finding the right person exist, if the particular vehicle series is still produced. Since software engineers are a scarce human resource, many manufacturers will be reluctant to put them on a task that is not considered their core business.

IT-equipment

The computing capacity installed on older locomotives is sometimes not sufficient to implement additional features. Since propulsion software is a real-time application, any modification slowing down the system too much may lead to dysfunctionalities in propulsion.

One hardware condition lies in the installed computing capacity which in older stock may not be sufficient in order to allow for a modification (cf. barriers).

The optimisation measure was favoured by the fact that the locomotive series was still in production at the time, so the software experts were available.