Individual tree-growth simulators that are to be used to support decisions in forest management must be able to provide forest growth forecasts for different stand treatments and forest management scenarios as well as giving results in terms of not only cubic metres or biomass, but also commercial assortments, including measures of wood quality. In the context of the ITM EU project, several known growth simulators were supplemented by incorporating additional modules to express a variety of thinning and harvesting algorithms. This allows studying the results pertaining to different management regimes. Their applicability has been considered in their dependence on the concepts of the specific growth simulation models within which they were to be implemented. Commercial assortments, as long as they only relate to log dimensions and log properties (which can be estimated using individual tree breast-height diameter, tree height and crown ratio), are easily implemented through the application of taper curves or the commonly used assortment tables. If other qualitative stem measures are needed to predict log quality, the relationships between the log quality distribution and the stem quality assessment are strong enough to encourage the use of modules to incorporate stem quality distributions into the growth simulation models. However, these relationships and classifications are very different in the different countries, regions and forest enterprises. Therefore a number of different logistic models have been presented to predict stem quality. Furthermore, it is deemed necessary and it is recommended that concrete relationships between stem qualities and log qualities are developed individually at a forest enterprise level.