Author: Ricardo H. Miyajima

Overview: The grapple saw is one of the fundamental machines in the full tree system. Being responsible for carrying out the tracing operation of the wooden beams. Assertiveness in the length of the wood is essential for the operation to deliver quality for the final product. As with other forest machines, evaluation from a technical and cost point of view becomes important in the production chain.

Question: Is there a difference in productivity and production costs for two grapple of different sizes??

Procedures Description: The methodology used was the study of times and motion, by the continuous time method. Two different sizes of grapple were evaluated for the tracing operation in a commercial eucalyptus forest.

Results Interpretation: Among the results, when comparing the two grapple for the productivity variable and for the production cost variable, there was no statistically significant difference.

Raw Data and Code used

• https://posit.cloud/content/10232967
• https://github.com/ricardomiyajima/my-research/blob/main/dados_garra.xlsx

Plots Generated

Figure 1. Box plot productivity

Figure 2. Box plot production cost

Figure 3. Correlation matrix for grapple 1

Figure 4. Correlation matrix for grapple 2