Will the real relationship between lean and safety/ergonomics please stand up?

Abstract

This paper provides a review of studies containing safety and ergonomic outcomes in lean manufacturing (LM) environments over the past 40 years. The aim is to identify effects from specific LM methods on specific safety/ergonomic outcomes, to understand the relationship in greater detail. One hundred and one studies containing one hundred and seventy outcomes were identified. Thirty-seven outcomes pertained to just-in-time (JIT) production, which contained twenty-three negative, eleven neutral, and three positive safety/ergonomic outcomes. Conversely, twenty-six outcomes pertained to 5S and consisted of twenty-four positive, two negative, and no neutral outcomes. The most common negative JIT outcome was stress and mental strain, while the most common positive 5S outcome was a tie between safety performance and hazard exposure. Studies containing other methods were fewer in number with more mixed outcomes. These findings suggest that individual LM methods, especially JIT and 5S, uniquely contribute to the safety/ergonomic outcomes attributed to LM.

Keywords: Occupational safety; Toyota production system.