Many sawmills in Canada are focused on the production of dimension lumber and use productivity levels as a measure of their success. Such mills are often unwilling to produce directly for remanufacturers or specialty product manufacturers because they believe that producing small volumes of off-sized lumber will negatively impact productivity.
This report describes the use of sawmill simulation tools to evaluate the impact on sawmill productivity of augmenting a product mix comprised of dimension lumber only with specialty sized lumber targeted toward producers of value-added wood products. The simulation tools utilised in this project were able to estimate productivity changes resulting from processing varying percentages of the log diet to higher valued, rough green products. When a relatively low percentage of logs were deemed suitable for non-standard sizes, and when the grade yields were assumed to be high, the impact on productivity was, as expected, minimal. However, productivity was observed to decrease with increasing percentages of logs from which higher valued products could be targeted, and also with decreasing grade yields.
Due to the inherent limitations of the present generation of sawmill simulation tools, namely their inability to consider defect other than wane, a number of simplifying assumptions were made regarding the proportion of logs suitable for higher valued products as well as grade yields from said logs. The results of this study must be viewed in the context of these assumptions.