Yes, we have standards in how we measure and make recommendations on different components. On our inspection sheets we have specific numbers for what would categorize a component as Green, Yellow, Red. A few examples would include:
brake fluid (moisture content %, visual condition), coolant (boiling point temperature, visual condition), tires (mm. tread depth, age, weather cracking, suppleness), disc brake pads/ drum brake shoes (mm. Thickness, glazing, seperation), battery (CCA output vs battery rating, age, cell condition),
There are also many items that have recommended manufacture service intervals such as transmission fluid, timing belts, fuel filter, water pump, etc.
On our quotes, we will specify if an item is Red or Yellow to help you understand the urgency of an item. Not all items are urgent, but if left too long they can have cascading effects that may cost you more money in the long run.. an example might be loose suspension/ steering components. This can lead to the wheels being out of alignment and cause uneven tire wear.