Problem
Just in 2020, the Bureau of Labor Statistics reported 21,1000 nonfatal injury and illness cases involving days away from work. This also equates to the incidence rate per 10,000 full-time workers being 191.6.
Refined Scope
With this in mind, this design case study aims to analyze and develop a product to mitigate these injury rates. After conducting field research by interviewing various janitors and custodians on UC Berkeley’s campus, our team prioritized redesigning the wet mop and its bucket as over half of those interviewed mentioned the strenuous nature of wet mopping.
How might we mitigate injury rates among janitors and custodians?
User Research
Surveys were conducted to ensure the design prioritized the users. The survey questions were divided into two topics: mopping tasks and mopping tools where the participants were given a range of questions to help us understand the potential physical problems caused by mopping and possible reasons.
Design Parameters
Due to the large range of body types of janitors and custodians, we aimed for our product parameters to account for the 5th percentile female to the 95th percentile male. The dimensional data was collected using the 1988 Anthropometric Survey of U.S. Army Personnel.
Success Criteria
Using the standardized risk assessment tools in industrial design, our success criteria will focus on the Revised Strain Index (RSI) and the Rapid Upper Limb Assessment (RULA). For RSI, reducing the exertion multiplier (EM) and the posture multiplier (PM) would be our main target as the current scores are at high risk for musculoskeletal disease. As for the RULA, we would focus on reducing the score for lower arm, wrist flexion, neck bending, and trunk bending as those are the highest scores according to our analysis. (More info on the analysis stated in the research paper)
Prototyping
initial sketches of possible mop redesign
2nd iteration of mop handle
2nd iteration of mop bucket design
Final Prototype
