While success runs require the specification of sample size and test duration, larger measurement activities demand additionally the variation of influencing factors. Test engineers have to decide about the number of levels and the corresponding values the factors are adjusted to:
- Road profile (city, country, motorway, off-road)
- Load and kind of load (load fixed or tank truck)
- Driving style (carefull, aggressive)
By the statistical methods of "Design of Experiments" (DoE) the design of the tests can be found fullfilling several optimality conditions, like minimum costs or minimum expenditure of time and material.