As others have said above, the general reliability of the units will help - the 555s have been specified to have very high miles between failure figures.
In addition to this, the new units are far more modular than the existing fleet - swapping parts out will be far easier and faster, which results in less time on the workshop roads per failure or maintenance cycle.
Like most modern fleets, the 555s will also feature much more advanced diagnostic capabilities. Many folks here seem to lament the introduction of computerised systems into railway rolling stock, however, when this is done a whole world opens up in terms of the data you can collect about each unit. Even 10+ years back I was working on systems with train manufacturers to remotely gather performance and fault data to enable better planning of maintenance work and faster troubleshooting - these days this is a feature that comes as standard. It's quite surprising the improvement in efficiency you can get from this.
The technology found in the current fleet is very much a product of the late 60's/early 70's, given that the design was pretty much locked in by the time the prototypes were produced and focused heavily on "proven" concepts. The 50+ years that have since passed have seen advances in rolling stock technology that are so significant it's hard to convey.
All of this combines to provide a fleet that will be available for service at a much higher rate. The 555s are not just "the next version" of the Metrocar, they're literally several generations ahead!
In addition to this, the new units are far more modular than the existing fleet - swapping parts out will be far easier and faster, which results in less time on the workshop roads per failure or maintenance cycle.
Like most modern fleets, the 555s will also feature much more advanced diagnostic capabilities. Many folks here seem to lament the introduction of computerised systems into railway rolling stock, however, when this is done a whole world opens up in terms of the data you can collect about each unit. Even 10+ years back I was working on systems with train manufacturers to remotely gather performance and fault data to enable better planning of maintenance work and faster troubleshooting - these days this is a feature that comes as standard. It's quite surprising the improvement in efficiency you can get from this.
The technology found in the current fleet is very much a product of the late 60's/early 70's, given that the design was pretty much locked in by the time the prototypes were produced and focused heavily on "proven" concepts. The 50+ years that have since passed have seen advances in rolling stock technology that are so significant it's hard to convey.
All of this combines to provide a fleet that will be available for service at a much higher rate. The 555s are not just "the next version" of the Metrocar, they're literally several generations ahead!