Preventive or Preventative.

The cost of rail infrastructure is high and it must be appropriately maintained to obtain peak benefits. Where maintenance is required to be regularly scheduled (e.g. months, cycles, hours, kilometres, etc.) it is called preventive maintenance.

See also reactive maintenance

To ensure quality outcomes,assessments need to be valid, reliable, flexible, and fair.

• Valid means that the assessment actually measures all of the unit of competency requirements.
• Reliable means that the assessment can be applied to others and will get the same results.
• Flexible means that opportunity is given for a candidate to negotiate certain aspects of their assessment with their assessor (e.g. the type of evidence to be presented) .
• Fair means that the assessment does not disadvantage a particular candidate or group of candidates. (For example, complexity of language prevents candidate from displaying competency at the level required).
• Cost effective means that the time, resources and material costs are reasonable for the assessment to be made.

A proceed aspect is usually the green aspect shown on signals. In some signals, especially shunting and other special purpose signals, another colour may be the proceed aspect.

See also:

Caution aspect and danger aspect