Modelling of process chains componentware, the example of timber harvesting

In order to survive modern forest enterprises must be productive and competitive. Both goals can be supported by modern information technologies (IT) designed to automate and deliver resource-efficient production chains. The permanent changes with which enterprises are confronted require rapid adjustments to meet new needs of customers. Consequently, IT-support must be designed for high adaptability and its components must be simple, robust and widely reusable. The process chain «timber harvesting» serves as an example to present one way of modelling elementary processes using software techniques, and how to combine them (like lego bricks) in a flexible manner to form entire process chains. Timber harvesting consists of various processes ranging from tree felling to stocking logs by the forest roadside. The sequence of these elementary processes may vary and similar tasks may be carried out by different methods and with different means. In order to model the output of timber harvesting the corresponding production chains must first be broken up into elementary processes. Mathematical models can then be developed to determine the respective output of each process. Subsequently, the models are transformed into componentware and joined together to productivity models of specific harvesting chains. The software components must comply with high quality standards and the standardization of input and output is, therefore, essential. Ideally the components should check that they match with a given task and fit the calculation. It is possible to link up models of elementary processes in various ways. Early attempts to model timber harvesting processes as software components were very promising, but eventually problems arose. It proved to be particularly difficult to delimit elementary processes accurately and implement the suitability tests. When applied with due diligence componentware can serve as a software base on which a flexible and useful collection of components can be built. Such systems can subsequently be integrated into commercially available applications to create forestry specific software.