TAWL Operator Simulation System (TOSS) Version 4.0

Abstract

This demonstration presents Version 4.0 of the Task Analysis/Workload (TAWL) Operator Simulation System (TOSS). TOSS is designed to support the development of models that predict operator workload using the TAWL methodology (see Hamilton & Bierbaum, 1990). During a TAWL analysis, the typical operation of a piece of equipment (the system) is identified and then decomposed into phases, segments, functions, and tasks. TOSS provides data base management of the information produced during the analysis. Additionally, the software uses the information provided to simulate the operation of the system and compute predictions of each operator's workload. The software can also be used for other simulation research (e.g., mission time line generation). The user describes the operation of a system using a bottom-up approach that combines tasks into functions and functions into segments. TOSS simplifies the user's description of the simulation by allowing tasks and functions to be identified as fixed or random in sequence; the program requires only the information necessary to simulate a specific category. TOSS predicts up to six task-related workload components by summing the values for each component across concurrent tasks and can generate a seventh component from any arithmetic combination of the first six. TOSS analyzes the peaks of the seven components using a thresholding function and produces statistics describing the percentage of time that any of the variables are higher than the threshold. Finally, TOSS produces an annotated half-second time line output for up to four operators. For every half-second of the simulation, the time line shows the tasks and functions that each operator is performing and the total workload for each of the components.