ForestTime: a mobile platform for IUFRO-standardized time studies in mechanized forest operations

Time studies remain essential for evaluating the productivity and operational efficiency of forest machinery. However, few mobile tools integrate field data collection, the internationally recognized IUFRO work-study nomenclature, cycle-level production records, and statistical analysis. This technical note presents ForestTime, an openly available Android application designed for continuous time studies of mechanized forest operations. ForestTime provides seven predefined machine profiles and a Custom profile for operations not represented in the predefined list. The application records events with millisecond-resolution timing, classifies productive, supportive, delay, and non-work time, registers production variables by cycle, estimates the required sample size in real time, and calculates Mechanical Availability and Machine Utilization. It exports a structured data package with an R analysis script for reproducible workflow. Metric and Imperial/US unit systems are supported, while exported Imperial/US measurements are additionally normalized to metric units. A demonstration study using a Tigercat LS855C feller-buncher comprised 7,353 valid event records, 6,426 productive cycles, and 91.3 h of workplace time. Mean felling-cycle time was 16.1 s, with a coefficient of variation of 49.1%. Mechanical Availability and Machine Utilization were 85.7% and 45.8%, respectively. ForestTime provides an integrated and reproducible workflow for field recording, data recovery, standardized time classification, and export of forest-machine time-study data.