The Siemens maintenance contracts are very expensive and you end up paying for a level of maintenance that may not be worth it.
Well the fact that Siemens units are constantly winning Golden Spanners left right and centre for the last decade and often taking up the top few positions all to themselves suggest that such contracts work.
Skimping on maintenance doesn't work out in the long run, go see any units that have had maintenance expenses cut back or have come off maintenance contracts and see their reliability fall in some cases quite dramatically and lots of short forms, which I'm sure people in this thread have experienced.
The difference between Bombardier's approach and Siemen's approach is reflected in the respective fleets that were born around the same time and their respective reliability figures. I understand that there are terms to these contracts, but they offer railways protection to ensure a certain availability of units or get compensation, the fact these were not around really when Alstom sold a load of questionable reliability stock is a real shame.
If we are really going to go down the road of keeping trains reliable is expensive so lets just not be bothered that much about it then there are seriously troubled times ahead for the railway, as the railwaymen a decade ago would never allow such things as these contracts were in part born out in the UK of the desire for operators to avoid issues experienced with various Alstom Fleets. The problem is the bid managers and theory knowners without any operational experience don't care.
Manufacturer maintenance contract margins are very much in operators crosshairs across Europe at the moment as that is the most obvious "fat" that can easily be trimmed to lean the overall system costs.
You will find the bid managers and those who know the price and theory of everything and the practice of nothing have them in their crosshairs. The Railway engineers and the operations people who come from that background and know the reality and practice have a rather different opinion.
Generally the only time people claim figures are massages is when there side is losing, when their side is winning then suddenly the figures they cast doubt on the accuracy of suddenly become reliable.