Analysis of five forest harvesting simulation models. Part II. Paths, pitfalls, and other considerations.

Abstract

This is the second of two papers describing the conclusions from a study to determine the state of the art in timber harvesting computer simulation modeling. Five models were evaluated -- Forest Harvesting Simulation Model (FHSM), Full Tree Field Chipping (FTFC), Harvesting System Simulator (HSS), Simulation Applied to Logging Systems (SAPLOS), and Timber Harvesting and Transport Simulator (THATS) -- for their potential use in southern forest harvesting operations. In Part I, modeling characteristics and overall model philosophy were identified and illustrated. This included a detailed discussion of the wood flow process in each model, accounting strategies for productive/nonproductive times, performance variables used, and the different harvesting systems modelable. In Part II user implementation problems are discussed. Those dealt with in detail are the following: What questions can be asked of the model. What are the modeling tradeoffs, and how do they impact on the analysis. What are the computer skills necessary to work effectively with the model. What computer support is needed. Are the models operational. The results provide a good picture of the state of the art in timber harvesting computer simulation. Much learning has occurred in the generation of these models, and many modeling and implementation problems have more » been uncovered, some of which remain unsolved. Hence, the user needs to examine closely the model and the intended application so that results will represent useable, valid data. It is recommended that the development of timber harvesting computer simulation modeling continue so that existing and proposed timber harvesting strategies can be adequately evaluated. Design criteria are proposed. (Refs. 22). « less