The effects of lean production on worker job stress

Purpose-This empirical paper seeks to address the neglected work condition aspect of lean production (LP) implementation, specifically the relationship between LP and worker job stress. Design/methodology/approach-The Karasek job stress model was used to link shopfloor practices to expected worker stress. The model incorporates the effects of job demands (physical and psychological), job control and social support. The study employs management and worker questionnaires, management interviews and structured plant tours. The response variable is total worker job stress-the sum of the physical and mental stress levels. The independent variable for the first question is the degree of lean implementation at the sites. Findings-The results are based on 1,391 worker responses at 21 sites in the four UK industry sectors. About 11 tested practices are significantly related to stress and an unexpected non-linear response of stress to lean implementation is identified. Results indicate that LP is not inherently stressful, with stress levels significantly related to management decisions in designing and operating LP systems. Practical implications-The hypotheses tests shed light on the relationships between LP practices and job stress, and reveal a significant managerial influence on stress levels. The regression model shows the scale and significant lean practices of this influence, with the work practices explaining 30 percent of job stress variations. The stress reduction and stress control opportunities identified in the study show the potential for designing and operating effective lean systems while also controlling stress levels. Originality/value-This is the first known multi-industry empirical study of the relationship of job stress to a range of lean practices and to the degree of lean implementation.