More than a Mean: Broadening the Definition of Employee Performance

The detrimental impact of performance variation within the mechanics of an organizational process is well established within the field of Operations Management. Furthermore, determining the causes of and resolutions for variability in the performance of system mechanisms has become a key focus for improving organizational performance (Womack & Jones, 1996). This dissertation extends this research as it examines the prevalence and nature of human performance variability within organizations, its relationship with individual mean work performance, and its impact on individual- and group-level performance within a manufacturing context. Moreover, this study investigates the relationships between individual difference variables (conscientiousness, cognitive ability, and three facets of work ethic) and individual work performance variability.

Results indicate that individual performance variability does exist in moderate to high levels within organizations. Additionally, the relationship between individual mean performance and within-person performance variability is not significant. Therefore, the two metrics may be providing different and important information about employee performance. Hierarchical regression results reveal that the average performance level of group members significantly predicts group level performance; however the relationship is moderated by the average level of individual performance variability of group members.

Finally, though individual performance variability is apparent in the study, the hypothesized relationships between individual performance variability and the individual difference measures were not supported. However, post hoc analyses reveal a number of potential avenues to pursue in determining whether individual differences (e.g., Agreeableness, Neuroticism, Extraversion, etc.) may be related to individual performance variability. These findings provide a starting point for research into the impact of human performance variability on individual and group level performance. The implications of these results and directions for future research are discussed.