Full text of this article is only available in PDF format.

Yrjö Nuutinen (email), Kari Väätäinen, Jaakko Heinonen, Antti Asikainen, Dominik Röser

The accuracy of manually recorded time study data for harvester operation shown via simulator screen

Nuutinen Y., Väätäinen K., Heinonen J., Asikainen A., Röser D. (2008). The accuracy of manually recorded time study data for harvester operation shown via simulator screen. Silva Fennica vol. 42 no. 1 article id 264. https://doi.org/10.14214/sf.264

Abstract

The aim of the study was to investigate the effect of work experience on the accuracy and variation of observers recording the operation time of a harvester. A simulated thinning operation using a harvester, shown as video via a television screen in laboratory conditions, was observed by 20 inexperienced students and 10 experienced work study researchers. All the observers timed the different work elements of the harvester work with special fieldwork timers. The duration of different work elements measured by the human observers were compared to the corresponding recordings by the harvester’s automated data collector. Although the inexperienced students made more measurement mistakes than the experienced researchers, the differences in measurement error averages were not statistically significant between the groups. However, the variances of tree specific errors were significantly higher in the measurements done by the students. As inexperienced recorders, the students were not able to properly record short work elements, which lasted a maximum of 4 seconds. Due to systematic measurement errors, there was a large variation in the timing structures of the work elements among all observers. Observers’ skills and experience seems to affect measurement accuracy and thus the derived results, especially in intensive time studies. Therefore, the recorder should receive detailed training and practical experience in timing of different work elements of forest operations. In the future, with the use of automated data collectors time studies with large, detailed and accurate data will be implemented. However, due to the varying timing conditions in the forest, manual data collection is still required because of its greater flexibility.

Keywords
accuracy of timing; mixed effects models; time studies

Author Info
  • Nuutinen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail yrjo.nuutinen@metla.fi (email)
  • Väätäinen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:
  • Heinonen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:
  • Asikainen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:
  • Röser, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:

Received 2 July 2007 Accepted 12 October 2007 Published 31 December 2008

Available at https://doi.org/10.14214/sf.264 | Download PDF

Creative Commons License

Register
Click this link to register for Silva Fennica submission and tracking system.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content

Your selected articles
Your search results