scholarly journals PERFORMANCE OF GRAPPLE SKIDDER IN DIFFERENT GROUND INCLINATIONS

FLORESTA ◽  
2018 ◽  
Vol 49 (1) ◽  
pp. 041
Author(s):  
Carlos Cezar Cavassin Diniz ◽  
Nelson Yoshihiro Nakajima ◽  
Renato Cesar Gonçalves Robert ◽  
Cícero Jorge Fonseca Dolácio ◽  
Franciele Alba da Silva ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Cycle Time ◽  
Steep Slope ◽  
Time Study ◽  
Forest Operations ◽  
Operations Planning ◽  
Operational Cycle ◽  
Forestry Sector ◽  
The Times ◽  
Slope Class

Land slope contributes to decrease the productivity in the forestry sector activities, including skidding operations. Thus, it is important to study it in order to improve the forest operations planning. Based on this hypothesis, this study aims to analyze the times of the operational cycle and the productivity of the skidder in slope terrain. The study was conducted in Pinus taeda plantations of a forest company located in the CentralWest region of the state of Paraná, Brazil, in three slope classes: flat to moderate, steep and very steep. The data were obtained by the continuous timing method in a time study. Productivity and mean effective cycle time were determined for the three slope classes. The results show that the search and load and the unloading slopes are the ones that consume less time between the activities evaluated in the operational cycle. Considering the slope classes evaluated, flat to moderate and steep require less time to perform all activities of the operational cycle, and their productivities are higher, when compared to the very steep slope class. The productivity of the very steep slope class was 35.3% and 45.0% lower than the flat to moderate and steep classes, respectively. Skidding with skidder on slopes over 26.1º should be avoided because the productivity is negatively influenced in this condition.

scholarly journals Influence of bifurcation on thinning, productivity and harvester production costs of Pinus taeda L.

2020 ◽  
pp. 1259-1263
Author(s):  
Carlos Cézar Cavassin Diniz ◽  
Romano Timofeiczyk Junior ◽  
Renato Gonçalves Robert ◽  
Eduardo da Silva Lopes ◽  
João Carlos Garzel Leodoro da Silva ◽  
...  
Keyword(s):  
Pinus Taeda ◽  
Cycle Time ◽  
Production Costs ◽  
Total Production ◽  
Plantation Forest ◽  
Operating Cycle ◽  
Operational Cycle ◽  
Time And Motion ◽  
Motion Study ◽  
Pinus Taeda L

In this work, we present that how bifurcation in Pinus trees can influence productivity and harvester production costs. Our example draws from one harvesting machine that works in thinning operations in forest plantations of Pinus taeda L. in a small Brazilian forestry company. To get daily productivity, we use the machine’s system, which provides such daily information as total production. We also used a time and motion study to obtain the meantime to cut, delimb, and process the tree stem into logs. In this way, we separated the normal trees from the forked trees to get the operating cycle time of the machine and get the productivity to the two types of trees. The continuous timing method was used for this purpose. The results show an increase of up to 22.9% in the operational cycle time for cutting forked trees, resulting in reduction of productivity of 5.58 m³ for each hour worked. The production cost increased by 23.3% on operation of forked trees, as the machine took more time to perform the partial activities of the operational cycle. This study can help many companies and contractors to calculate the appropriate productivity and production harvest cost according to the type of tree stems from the plantation forest.

Analysis and Reduction of the Waste in the Work Process Using Time Study Analysis: A Case Study

2014 ◽  
Vol 660 ◽  
pp. 971-975 ◽  
Author(s):  
Mohd Norzaim bin Che Ani ◽  
Siti Aisyah Binti Abdul Hamid
Keyword(s):  
Cycle Time ◽  
Lean Manufacturing ◽  
Value Added ◽  
Time Study ◽  
Study Approach ◽  
Root Cause ◽  
Wide Range ◽  
Unit Of Work ◽  
Time Required ◽  
The Impact

Time study is the process of observation which concerned with the determination of the amount of time required to perform a unit of work involves of internal, external and machine time elements. Originally, time study was first starting to be used in Europe since 1760s in manufacturing fields. It is the flexible technique in lean manufacturing and suitable for a wide range of situations. Time study approach that enable of reducing or minimizing ‘non-value added activities’ in the process cycle time which contribute to bottleneck time. The impact on improving process cycle time for organization that it was increasing the productivity and reduce cost. This project paper focusing on time study at selected processes with bottleneck time and identify the possible root cause which was contribute to high time required to perform a unit of work.

A computer approach to finding an optimal log landing location and analyzing influencing factors for ground-based timber harvesting

2007 ◽  
Vol 37 (2) ◽  
pp. 276-292 ◽  
Author(s):  
Marco Contreras ◽  
Woodam Chung
Keyword(s):  
Influencing Factors ◽  
Road Construction ◽  
Timber Harvesting ◽  
Volume Distribution ◽  
Forest Operations ◽  
Operations Planning ◽  
Factors Influencing ◽  
Gis Data ◽  
Harvest Volume ◽  
Design Factors

Locating a log landing is an important task in forest operations planning. Several methods have been developed to find an optimal landing location and compute a mean skidding distance, but they simplify harvest unit attributes and do not simultaneously consider multiple design factors influencing optimal landing locations. In this study, we introduce a computerized model developed to determine the optimal landing location for ground-based timber harvesting. Using raster-based GIS data, the model finds skid trails from stump to each of candidate landings and selects the best landing location that minimizes total skidding and spur road costs. The model is applied to several hypothetical harvest units with different terrain and harvest volume attributes to analyze the effects of design factors influencing optimal landing locations. Unit boundary shapes, volume distribution, the presence of obstacles, terrain conditions, and spur road construction are considered as influencing design factors.

scholarly journals Accuracy of timing in some time study methods

1978 ◽  
Vol 50 (1) ◽  
pp. 1-66 ◽  
Author(s):  
Aarne Pehkonen
Keyword(s):  
Break Point ◽  
Reliable Estimate ◽  
Time Study ◽  
Sharp Decline ◽  
Simple Manner ◽  
Average Deviation ◽  
Use Of Time ◽  
Measuring Accuracy ◽  
The Times ◽  
The Moment

With measured times varying between 3 ... 115 cmin (average 19 cmin) the average deviation in the use of time study instruments (approximately 63 000 times) was 0,83 cmin (6,4 %). As the times became shorter, below 15 ... 20 cmin, there was a sharp decline in the relative measuring accuracy. The measuring accuracy improved when conditions at the study location were favourable to the observation of the break point or limited the reception of information other than that coming from the study object. The measuring accuracy of watches with pointer display improved if the pointer could be stopped at the moment of measuring and the result read out afterwards. The variables describing the characteristics of the test person, e.g. age, basic schooling, degree of training and intelligence, were correlated with the measuring accuracy. The measuring of times did not seem to require special techno-mechanical talent. With the aid of variables that describe the characteristics of the test persons and that can be determined in a simple manner it is not possible to give a reliable estimate as to how well a specific person is suited to the task of a time investigator. This problem may be solved by using, for example, a work test based on simulation.

scholarly journals Determination of standard times for process improvement: A case study

2017 ◽  
Vol 7 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Mehmet Akansel ◽  
Betul Yagmahan ◽  
Erdal Emel
Keyword(s):  
Process Improvement ◽  
Business Environment ◽  
Time Study ◽  
Work Study ◽  
Production Lines ◽  
Productivity Improvement ◽  
Work Sampling ◽  
Increase Productivity ◽  
The Times

Abstract The companies are required to use proper methods to reduce their costs and increase productivity levels so that they can survive in the fast-changing competitive conditions of the existing business environment. Work study is one of those highly effective productivity improvement methods in labor dependent industries. Determination of standard times, which is one of the important steps of a work study, provides a critical input for process improvement activities within companies. This work is based on a project which included determination of standard times as one of the earliest steps of process improvement activities in a steel-pipe manufacturing company. In systems analysis phase which was performed as the first step, it was observed that long delays occurred on production lines and an evenly distribution of workload among workers was not achievable most of the times. In order to alleviate these problems, all labor-intensive jobs within the system were identified and depicted in process charts. Standard times of the processes were determined by using time study and work sampling techniques. Next, line balancing problems associated with uneven workloads were addressed using these standard times data and some solutions were obtained. All in all, the framework which provided promising results in this pilot study was recommended to be broadened to the entire manufacturing system of the company. Keywords: time study, work sampling, standard time, productivity.

scholarly journals Productivity of a Portable Winch System Used in Salvage Logging of Storm-Damaged Timber

2019 ◽  
Vol 40 (2) ◽  
pp. 311-318
Author(s):  
Ebru Bilici ◽  
Güryay Volkan Andiç ◽  
Abdullah Emin Akay ◽  
John Sessions
Keyword(s):  
Cycle Time ◽  
Winter Season ◽  
Field Measurements ◽  
Statistical Analyses ◽  
Time Study ◽  
Storm Damage ◽  
Western Turkey ◽  
Salvage Logging ◽  
Ground Slope ◽  
The City

Storm damages result in serious losses in many regions, primarily by stem breakage or blowdown. Extraction of storm-damaged trees often requires more difficult than normal skidding activities due to obstacles created during the storm. In this study, the productivity of a portable winch was evaluated as a possible alternative to recover storm-damaged timber. Field measurements were conducted in the Alabarda Forest Enterprise Chief located near the city of Kütahya in western Turkey, where storm damage often occurs during the winter season. The time study was implemented in two slope classes (35% and 55%) and two skidding distances (40 m and 60 m). All timber was skidded uphill. A regression mode was developed that related productivity to log volume, ground slope and skidding distance. The highest percentage of total cycle time was observed for skidding logs to the landing. The highest productivity (3.96 m3/hour) was found at the shorter skidding distance (40 m) and the lower ground slope (35%). Statistical analyses indicated that productivity was most highly affected by log volume, followed by skidding distance and ground slope. Larger log loads increased productivity, while both longer skidding distances and steeper slopes reduced productivity.

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