In elevated assembly rooms with a mounting height of over 10m, reflector luminaires with high pressure lamps are favoured, whereas fluorescent lamps are deployed with less than 10m mounting height. The degree of protection of the luminaire and safety demands are dependent upon operational conditions. In situations with low dirt conditions, indirect projected systems can be used among others; they offer simple maintenance with respect to relamping. Parallel rows of trunking systems are favoured for assembly lines. They guarantee a uniform level of lighting in the assembly area and a light incidence that avoids annoying glare on metal surfaces. In areas where VDU's are used, extensive surface lighting with e.g. a micro-prism structure is preferable, reducing the danger of direct and reflected glare. For inspection work on the other hand, luminaires with a least possible light aperture area are most suitable.