Application of time study results at computer-aided logging

Research has been done on the system of differentiated technical norms (average times) for determination of the total working time which is necessary for cutting and primary wood conversion per tree, performance and operational power saw time per tree, at cutting and primary wood conversion in the mountainous and submountainous forests of Croatia. The results of the research are a system of parameters of regression equations differentiated according to the chosen criteria. Application of the research has encouraged introduction of computers as modern and efficient tools for improvement of preliminary work at cutting and primary wood conversion. By means of developed programme routines, experts in preparatory work at forest exploatation can create, according to the data on the trees marked for cutting, the indices of the cutting and primary wood conversion plan (time per tree, total working time of all marked trees and operational power saw time). By choosing alternatives in the cutting plan performance, a forestry expert can have a relatively higher influence on the rate of annual realization of the felling plan and on planning the utilization of the work factors. The paper contains the expected effects of computer application of time study results, and the basic assumptions of developing the cybernetic model of production management on the cutting and primary wood conversion stage.