Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

The time within which, accordingly to its application, machine works, and an object of work and working groups are under load, is the effective active time. The purpose of the research was the order statistics of effective active time of limbing and conversion at chainsaw use. The removed trees were moderately diversified from the point of view of effective active time of limbing and conversion. The negative skewness coefficient qualified the distribution of effective active time of limbing and conversion  as weak left-side asymmetry in variant 1 (the limbing included cutting of trees’ crowns and all branches). The positive skewness coefficient qualified the distribution of effective active time of limbing and conversion as weak right-side asymmetry in variant 2 (limbing included cutting of tree crowns and only thicker branches).