Identifying Problems and Generating Recommendations for Enhancing Complex Systems: Applying the Abstraction Hierarchy Framework as an Analytical Tool.

The process of identifying problems and generating recommendations for complex systems using conventional methods is usually conducted based on incompletely defined work requirements. The sheer mass of data generated from these methods becomes unwieldy to manage in a coherent form for analysis as the complexity of systems rises. The present study adopts J. Rasmussen's (1985) abstraction hierarchy (AH) framework as an analytical tool to identify problems and pinpoint opportunities to enhance complex systems. AH was used to analyze an aircraft automation system in order to further identify breakdowns in pilot-automation interactions. Four steps demonstrate this approach: developing an AH model for the system, mapping the data generated by various methods onto the AH, identifying problems based on the mapped data, and presenting design recommendations to enhance the current system. Results showed that the breakdowns lay primarily with automation operations that were more goal directed. Identified root causes include incomplete knowledge content and ineffective knowledge structure in pilots' mental models, lack of effective higher-order functional domain information displayed in the interface, and lack of sufficient automation procedures for pilots to effectively cope with unfamiliar situations. The AH appears to be a useful analytical tool for systematically identifying problems and suggesting opportunities for enhancing complex systems.