En analys av SCA Skog AB's metod för egenuppföljning av gallringar

Sammanfattning: A high quality is highly requested in today's thinnings, since these are the base for continued value development of the forests. Thinning quality often means a minimization of damages on soil, stems and roots during the cutting. One way to reach a high quality is to set up goals that will be followed up after the cutting is made. Self-checking gives information of the machine drivers work and guarantees the customers a good quality of work. This has become a useful method in order to keep up in the competition with other companies about the desirable wood raw material. The purpose of the study was to analyze the effectiveness in SCA's new instruction for self-checking of thinning. The study was devided into three different parts: 1) A following-up of thinnings in the form of a fieldwork with 23 stands that had been chosen by sampling. First thinnings with a pine proportion > 50 % were selected. In this part a statistical comparison was made between the data that the machine drivers collected and the data that was collected during the thinning following-up study. 2) Interviews to explore the machine drivers opinions about self-checking. In this part 13 machine drivers took part, of which seven were entrepreneurs and the rest were employees to entrepreneurs or employees from one of SCA's own thinning teams. 3) Interviews with five production leaders and one district manager to explore their opinions about the efficiency of the self-checking. The study showed that the new and highly simplified method for self-checking of thinning within SCA works well. The basal area after thinning was overestimated with 1,3 m2/ha (8 %) by the drivers. Average diameter (6 %), average height (11 %), damage proportion (one percent unit), strip road width (4 %) and strip road proportion (four percent units) were underestimated. The strip road distance was the same at self-checking as that measured in this study. The strip road width was broader than the norm for SCA and the damage proportion exceeded in some cases 5 %. The study indicated that drivers considering themselves to be careful with self-checking had better results than those considering themselves more careless with their measurements. The machine drivers had a positive attitude towards the new instruction. They said that the method involved a simplification and saved time, because many measurements could be done directly from the machine. They also had a positive attitude towards self-checking as a tool to calibrate themselves, but lacked appreciation and encouragement from the company. The production leaders have started to see a certain improvement of the machine drivers submitting the self-checking records since the new instruction was taken in operation. The study shows that there is a possibility to further improve the self-checking and make it more efficient. Within the area of data- and map management there are improvement possibilities, for example in developing a digital self-checking record.