Application of Hierarchical Goal Analysis to the Halifax Class Frigate Operations Room: A Case Study

Abstract : This paper reports on the first application of Hierarchical Goal Analysis (HGA) [1], a relatively new approach to requirements analysis for complex systems, to naval command and control. HGA, applied to 11 positions of the Canadian Forces Halifax Class Frigate operations room, decomposed three top-level goals to a full goal hierarchy of 563 goals. The hierarchy ranged from four to nine levels deep, with an operator assigned to each goal. The HGA process concluded with a stability analysis for identifying potential goal conflicts and an upward flow analysis for identifying requirements for feedback between operators. An examination of the stability analysis revealed that the current design of the operations room includes few sources of instability where multiple operators compete for control of the same variable. The upward flow analysis revealed that the requirement for feedback from operators assigned to lower-level goals to operators assigned to higher-level goals is relatively high, and the operations room could benefit from review and redesign. The goal hierarchy, operator assignments, stability and upward flow analyses, and proposed solutions were reviewed by subject matter experts. While used to model an existing system, the present application of HGA appears to be especially useful in providing a basis for evaluating a system design and developing design recommendations.