A symbolic framework, tradeoff matrix, and empirical studies of procedures and procedure following

Currently, procedures are designed based on experience rather than engineering principles, which lead to inconsistency during implementation. Also, there are no standard unambiguous definitions of procedure characteristics. Hence, it is difficult to compare across research studies on procedures and procedure-following. Additionally, basic knowledge regarding the effect of factors on system operation such as procedure detail, the presence of a time constraint, operator experience, and operator flexibility to deviate from procedures, is unknown. In order to address these problems with procedures and procedure-following, a conceptual model was developed to synthesize past research on procedure-following. The conceptual model helps in understanding procedure following based on the final outcome of the implementing the procedure, rather than on compliance or noncompliance. In order to address the recommendations suggested to improve performance from past research, a symbolic framework was developed to define procedure characteristics consistently across different fields of application. Further analysis of the procedure characteristics definitions in the symbolic framework led to the understanding that there are interactions among the procedure characteristics. A procedure designer trade-off matrix was designed to identify the interaction among thevarious procedure characteristics. The matrix shows how improving certain characteristics could impair other procedure characteristics. Based on the interactions established in the trade-off matrix, the factors affecting procedure-following that can be independently controlled by procedure designers were identified, including the presence of a time constraint, operator experience, and operator flexibility to deviate from procedure. Two human subject experiments were conducted to understand the effect of these factors on performance during procedure-following. Results of the experiments suggest that introduction of a time constraint reduces overall performance, and operator experience improves performance when a time constraint is present. No substantial conclusion was drawn regarding the effect of operator flexibility to deviate from procedures. This research provides a trade-off matrix to guide procedure designers in designing procedures. The definitions in the symbolic framework can be used to compare procedures and also compare research studies results based on the definitions in the symbolic framework. The results of the human subject experiment help in understanding the effect of the independently controlled factors on system performance.