Issue 4 | Main types of specifications
Environmental criteria (specifications) can be classified according to their degree of quantification. For a PTA, it is usually preferable to choose a functional approach instead of concrete design provisions. In a few cases, however, it is proposed to make provisions for the vehicle design or for modes of operation (see chapter 5.3). In those cases, specific quantifiable indicators may be applied which refer only to a specific component of the system. According to UIC Leaflet 345, four degrees of quantification can be distinguished:
- Target specification
- Performance specification
- Compliance specification
- Design provision.