Ergonomics and Musculoskeletal Disorders

Step 5: Evaluate Your Ergonomic Program

Key points

  • Follow up on your workplace interventions to ensure they are effective.
  • Measure the effectiveness of your intervention using techniques like the cost-benefit analysis.
  • Calculate the return on investment (ROI) of your intervention to inspire efficacy in the program.
A keyboard key with the words "Employee Wellbeing".

Follow up on your intervention

Follow up on your interventions to ensure the controls you implemented really reduce or eliminate the WMSD risk factors.

Ensure that no new WMSD risk factors were created in the process. Workers may be sore from doing their jobs differently by using new muscle groups. Check with workers after one week and again after one month following an implementation.

Adjusting to work is also important for new and return-to-work employees. This is especially true for tasks that are highly repetitive. These tasks include such as paced work on a fast conveyor line or picking items with a time standard.

New employees need about two weeks to condition their muscles. During the adjustment period new hires or employees returning from a long absence to report muscle soreness.

Determine the effectiveness of your intervention

You can use a variety of techniques to measure the effectiveness and benefits of your ergonomic program. Compare the following data before and after the intervention:

Administrative

  • Job analyses
  • Checklists
  • Symptom surveys
  • OSHA form 300 logs
  • Employee absentee rates
  • Turnover rates
  • Workers' compensation costs

Results

  • Productivity indicators
  • Quality of products and services
  • Total savings

Remember that workers will not experience the benefits of your ergonomic program immediately. It can take months for old WMSD symptoms to disappear. You will need to modify your intervention if new WMSD symptoms appear.

Cost analysis

The equations and examples below will help you to see the economic value for your ergonomics program(s). You can use the benefit-cost ratio to determine whether or not your investments in the program(s) will be cost effective. By calculating the Return on Investment (ROI) and conducting a cost-benefit analysis, you can better plan the implementation of your program.

Benefit-cost ratio

The benefit-cost ratio measures the present or annual worth of a project or proposal's benefit cost related to the initial cost.1 If the ratio is greater than the investment, it shows benefits outweigh the cost. If the ratio is equal, then the investment is a break even. If the ratio is less than the investment, it shows the cost outweigh the benefits.

a math formula with benefit cost ratio on the left and a quotient made up "worth benefits/worth cost" on the right.
Benefit cost ratio.

Cost-benefit analysis

Cost-benefit analysis (pay-back period) is the amount of time it takes for benefits to pay back on the cost of investment. It includes factors outside of investment such as savings from injuries prevented.

Example problem

Reviewing cost factors shows the current system has the potential for employees injuring themselves from manual lifting when loading the forklift. By changing to a new system, you can avoid compensation claim costs from potential sprains ($30,000) and back strain ($33,000).

This is a total savings of $63,000 for the year. The cost-benefit is the cost of equipment divided by the estimated benefits for one year. The saving benefits are injury savings plus increased productivity over the year. In this case increased productivity is $69/day*365days/year=$25,185.00/year.

Cost-benefit analysis

A math equation with cost benefit time on the left, and a quotient on the right made up of "cost" over "total savings (benefit)."
Cost-benefit analysis.

Total savings benefits

Total Cost of Equipment = $53,800

A math equation with "$63,000/year + $25,185/year" on the left side, and $88185/year on the right side after the equals sign.
Total savings benefit.

Payback period

A math equation with "$53,800 / $88,185/year" on the left side, and "0.61 year ~ 7.3 months" on the right side.
Cost benefit (payback period) accounting for injuries prevented.

Return on investment

Return on investment (ROI) is calculated as the amount of time to recover the cost of the initial investment.

Return on investment

A math equation with "ROI time" on the left side, and a quotient on the right side with "initial cost / savings (time interval)."
Return on investment.

Example problem

Metals Recycling Company wants to replace their current loading dock system to transport scrap metal with new scrap conveyors. The company runs production 365 days per year. The total for two new scrap conveyor systems installed is $53,800. They estimated that the new system saves a total of 3 hours per day. Their employees are paid $23.00 per hour so savings per day is $69 per day.

Total Cost of Equipment = $53,800

A math equation with "3hr / day * $23 / hr" on the left side, and "$69 / day" on the right side.
Savings on time.

Return on investment example

A math equation with "$53,800 / $69/day" on the left side, and "780 days ~ 2 years, 50 days" on the right side.
Return on investment example.

For more assistance with insurance policies and requirements, view Workers' Compensation Insurance: A Primer for Public Health.

  1. Badiru, Adedeji B. and O. Omitaomu. “Computational Economic Analysis for Engineering and Industry.” (2007).