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Based on data collected from seven commercial harvesting operations in Western Australia, the study developed a productivity model for chain flail delimber&#8315;debarker&#8315;chippers (CFDDCs) used in blue gum (<i>Eucalyptus globulus</i> Labill.) plantations. The tests covered 45 h and 3395 cycles, and were conducted using time-study techniques. Despite the observational character of the study and the dampening effect of multi-tree processing, the study yielded a viable prediction model for estimating CFDDC productivity as a function of mean tree size, tree form, bark&#8315;wood bond strength (BWBS), and machine type. Productivity increased with mean tree size on a logarithmic scale, and was lower for poorly formed trees and high BWBS. Under equal conditions, a separate delimber&#8315;debarker and a chipper were 10% to 20% less productive than the integrated delimber&#8315;debarker&#8315;chipper. Productivity estimates were consistent with those reported in published case studies of CFDDCs used in planted <i>Eucalyptus</i>. Neither this study nor any of the previous ones could offer a reliable estimate of long-term machine utilization, which would be an ideal subject for future research.