This mixed-method retrospective case study examines the implementation of a systems thinking intervention – The Manufacturing Game™ – as part of a comprehensive approach to “Proactive Manufacturing” and workforce involvement in continuous improvement at an American oil refinery.  Notable gains in local reliability metrics such as Mean Time Between Failure were achieved as a result of these efforts, which contributed to financial, safety, and environmental performance.  At the same time, the overall impact of the program on the refinery’s performance is ambiguous, confounded by simultaneous investments in the physical capital and capacity of the plant that generated significant value.  This ambiguity created interpretive flexibility for employees of the plant, who were able to both interpret and shape the continuous improvement activities based on prior political divisions, mental models, and interpretive biases.  A structurational perspective is employed to understand these emergent and unintended consequences.  From this perspective, a speculative model of relational conflict that undermines workforce participation in continuous improvement is developed.