the luminous fluxdeclinedue to failure oragingof lamps
the possiblecontamination of
theindoor and outdoorconditions that maycontribute topollutionand aging
Duration of themaintenance
Lifetime of a plant
Example: In amaintenance factorof 0.5, a system mustgeneratetwice theluminous fluxat the beginning,so thatit providesto
first maintenancelevel required intherelevantstandardillumination.The extrabrightnessin the installationisalsoreferred to aslight outputbuffer.