New Zealand Journal of Forestry (2001) 45(4): 29–33
©New Zealand Institute of Forestry
Log sawing optimisation directed by market demands.
C. Todoroki and M. Ronnqvist
Christchurch, New Zealand: New Zealand Institute of Forestry.
Throughout the forest-to-mill supply chain there are many instances where provision of accurate data can enhance decision-making and profitability. Software tools designed to aid decision making include FOLPI, MARVL and AUTOSAW. FOLPI can be used to optimise stand harvest scheduling and log allocation to markets, MARVL provides optimal log bucking solutions that maximise the total value of logs obtainable from each stem, and AUTOSAW can provide optimal sawing solutions that maximise total lumber volume or value yields.
In generating optimal volume or value solutions, both MARVL and AUTOSAW assume open market conditions. Whether cutting stems into logs, allocating logs to processes, or sawing logs into boards, key drivers in the solution process should take account of market demand. While FOLPI already addresses this at the strategic and tactical levels, work is currently underway to include market demand in AUTOSAW.
This paper reports on a prototype system that is implemented and tested in the AUTOSAW log sawing simulation system. The "product optimisation" system dynamically controls production to fulfill lumber orders by feedback from regularly updated production tallies.
Graded yield from volume-, value- and product-optimised solutions was generated from the simulated sawing of pruned Pinus radiata logs using three orderbooks that consisted of lumber orders specified by grade and volume. In each case, the prototype required fewer logs to satisfy each orderbook than either volume-or value- optimisation. Furthermore, over-production of unordered products was significantly reduced. In practical terms, these results suggest that potential gains at the sawmill may be obtained through the purchase and processing of fewer logs to meet the same demand and an accompanying reduction in storage requirements for surplus products.