Journal ArticleDOI
Combined primary and secondary log breakdown optimisation
C L Todoroki,E M Rönnqvist +1 more
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Linked dynamic programming formulations are developed that can be modified to maximise either total value of boards (incorporating quality) or total volume and results from simulations indicate that significant increases in value are possible when quality is considered.Abstract:
At sawmills logs are converted into boards by a series of cutting operations. Primary cuts reduce logs into slabs of wood, secondary cuts produce boards. Boards incorporating natural defects such as knots (branch sections) are inferior to clear boards. The aim of the sawmill is to cut logs to produce boards of greatest value. However, when logs are pruned, knots are only exposed after primary cutting. This complicates the conversion problem. To effectively convert logs into boards the interrelated effects of the cutting phases must be recognized. In this paper linked dynamic programming formulations are developed. The inner (secondary) formulation determines the optimal sequence for cutting a slab into boards. The result is passed to the master (primary) formulation that determines the optimal sequence for cutting the log into slabs. The objective functions can be modified to maximise either total value of boards (incorporating quality) or total volume. Results from simulations indicate that significant increases in value are possible when quality is considered.read more
Citations
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Journal ArticleDOI
Dynamic Control of Timber Production at a Sawmill with Log Sawing Optimization
TL;DR: The efficiency of the system was tested with three orderbooks via comparisons with volume- and value-optimized solutions obtained from sawing pruned Pinus radiata D. Don logs, and underproduction was eliminated and overproduction reduced.
Journal ArticleDOI
Internal supply chain management in the Chilean sawmill industry
Marcos Singer,Patricio Donoso +1 more
TL;DR: In this article, the authors investigate a collaborative approach, and propose a model for optimizing production and inventory planning decisions within a system of plants, and apply the model at 11 Chilean sawmills to evaluate whether they can benefit from operating in a more integrated manner.
Journal ArticleDOI
Scheduling production for a sawmill: A comparison of a mathematical model versus a heuristic
TL;DR: A mathematical model, which calculates the volume and the schedule of various types of logs, and a heuristic that solves the problem by systematically applying the criteria used by a sawmill programmer in southern Chile are used.
Journal ArticleDOI
Automated Planning and Optimization of Lumber Production Using Machine Vision and Computed Tomography
TL;DR: An automated system for planning and optimization of lumber production using Machine Vision and Computed Tomography and a prototype implementation shows significant gains in value yield recovery when compared with lumber processing strategies that use only the information derived from the external log structure.
Journal ArticleDOI
Increased Yield in Sawmills by Applying Alternate Rotation and Lateral Positioning
TL;DR: In this article, the authors analyzed the potential to increase volume yield in Swedish sawmills by applying the optimal combination of rotation and parallel positioning in cant and deal saw, and found that an increase in average volume yield by 4.5 percentage points would enable a typical Swedish sawmill to produce a further 17,300 m 3 of boards per year and thereby increase potential annual income by US$3.7 million per year.
References
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Journal ArticleDOI
Log Bucking and Lumber Manufacturing Using Dynamic Programming
Bruce Faaland,David Briggs +1 more
TL;DR: The process of converting a tree into finished lumber involves several interrelated steps, but this paper considers the two activities together as a single production system which allows for variations in tree shape and quality which could be recorded by modern electronic scanners.
Journal Article
CORY: A Computer Program for Determining Dimension Stock Yields
TL;DR: In this article, the authors present a program for calculing rendement et les meilleures sequences de sciage de bois feuillus, in order to calculate le rendement.
Journal Article
The Value Versus Volume Yield Problem for Live-Sawn Hardwood Sawlogs
TL;DR: In this article, the potential conflict between value and volume maximization in sawing hardwood sawlogs by the live sawing method was analyzed and the potential average loss of $2 per sawlog was indicated if volume yield was maximized at the expense of value yield.
Journal ArticleDOI
Secondary log breakdown optimization with dynamic programming
C L Todoroki,E M Rönnqvist +1 more
TL;DR: Comparisons with existing edging and trimming procedures show that substantial reductions in solution time can be achieved, and some procedures for determining the optimal cutting of flitches into graded dimensional boards are described.