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

Area of Science:

• Industrial Engineering
• Occupational Safety and Health
• Manufacturing Systems

Background:

• Lean manufacturing (LM) is widely adopted to enhance efficiency.
• However, its impact on safety and ergonomics requires detailed investigation.
• Understanding specific LM method effects is crucial for worker well-being.

Purpose of the Study:

• To systematically review safety and ergonomic outcomes in LM environments over 40 years.
• To identify the specific effects of distinct LM methods on these outcomes.
• To elucidate the nuanced relationship between LM practices and worker safety/ergonomics.

Main Methods:

• A comprehensive literature review was conducted.
• 101 studies encompassing 170 safety/ergonomic outcomes were analyzed.
• Outcomes were categorized by LM method (e.g., Just-in-Time, 5S) and their nature (positive, negative, neutral).

Main Results:

• Just-in-Time (JIT) production was associated with 23 negative outcomes (e.g., stress, mental strain) and 3 positive.
• 5S methodology yielded predominantly positive outcomes (24 positive vs. 2 negative), notably improving safety performance and reducing hazard exposure.
• Other LM methods showed fewer studies and more mixed results.

Conclusions:

• Individual LM methods have distinct impacts on safety and ergonomic outcomes.
• 5S demonstrates a strong positive correlation with improved safety and reduced hazards.
• JIT production, conversely, is linked to increased risks such as stress and mental strain, necessitating careful implementation strategies.