In North-America, the lumber industry almost solely produces commodity products (i.e. products with standard dimensions and properties). Yet some customers also want products with very specific characteristics. The current situation in softwood lumber manufacturing does not enable the sawmills to know how the introduction of a new product will affect quantities for the other products they are also producing (i.e. they do not know how the introduction of a new product will affect the global "mix of products" of the company). This is due to some characteristics of the lumber manufacturing process (divergent processes, co-production, automation). We propose a decision-making framework for tactical planning in order to take into account the demand for specific products never produced by the company. This framework connects a log breakdown simulator and a tactical planning model. Through an industry-inspired case study we developed, we show the potential and the relevance of the approach.