Bidragsanalys av dimensioner och postningar
en studie vid Vida Alvesta
An old and well known problem in sawmilling is to determine which dimensions /products those are most profitable to produce. Existing optimization models maximize the value of the log. In other words, based upon the market prices of the dimensions the models calculate the best way to split the log. Yet there is a great uncertainty if the most well paid dimensions really are the most profitable to produce. The costs of the process from lumber to sawn products are hard to determine and are therefore often left out from the optimization process.
In this study the economic contribution of different dimensions/products are analysed. These occur through taking the direct-costs into account and then add the capacity cost that the dimensions give rise to when occupying the planner. In this way a ranking of the dimensions is done, a ranking that also takes the section that limits the production of the sawmill, the planner, into account. The results show that it is in fact the dimensions with high market prices that are the most profitable to produce. The production costs seem to differ quite little while the market prices seem to differ all the more.
In the next step all the costs and revenues are calculated back to the saw patterns. Although it is in fact the patterns that state which dimensions that will be produced. The results indicate that the saw patterns in use are not always the most profitable alternative. Instead it is rather the saw patterns with the best volume yield that are used.
Based upon these results it seems to be quite a lot of opportunities to improve the production and the profitability. For example, by direct the production towards certain well paid dimensions and also if possible use the saw patterns with the highest profita¬bility.