Abstract
A proper understanding of human performance characteristics is a prerequisite for designers of complex systems. Although human factors texts provide some insights into basic performance issues, the emergence of highly automated computing systems have fundamentally altered the way humans work. The purpose of this article is to present a research approach to quantify and analyze human performance within a complex, time-critical system. The approach is centered on a measurement construct, called a time window, which enables a functional relation between constraints on operator activities and time availability. A blackboard model is developed as the mechanism to generate, maintain, and complete time windows. Moreover, an object-oriented methodology is described that implements the blackboard model within a realistic task context. To demonstrate the utility of time windows, an existing implementation in a real-time human-in-the-loop simulation is also described. Using time window outcomes, some cursory analyses are completed to exhibit the potential of the construct.