"There isn't one particular school of thought in ergonomics as to the "best" way to implement ergonomic improvements.
There are some methods that are more rigorous and science-based than others, and naturally are more time-intensive. There are also stripped-down ways to get the job done faster and easier.
Ergonomists have various approaches depending on the situation. It may not be necessary to use analysis tools, to create elaborate written descriptions of before and after conditions or to measure and document the magnitudes of ergonomic stressors. These are all useful parts of a disciplined ergonomics process, but not necessarily do-or-die necessities for all ergonomics work.
One generally will see these aspects detailed in the work of outside ergonomics consultants who provide full documentation to their clients so the clients get as much beneficial information as possible. In such situations there is a need to provide the facts that back up recommendations for changes – before-and-after measurements so results can be weighed as successes or failures, data to show if a problem might need more work, comparative information for setting spending priorities, etc. This fully documented technical approach also is virtually mandatory for in-house ergonomics staff at larger companies.
Measurements usually are taken before and after ergonomic changes have been implemented. Measurements include various joint angles, estimates of hand gripping force and cycle times. These numbers can be plugged into analytical tools, the most well-known including Snook push-pull tables, the NIOSH “Lifting Equation,” the Job Strain Index and the Rapid Entire Body Assessment, comparing the measured states against established criteria. We also might see videos or still photos taken before and after as part of the documentation package.
A leaner approach to ergonomics might cut to the chase, hit the obvious issues first and mainly save that sort of technical deliberation and documentation for prioritizing where tightly budgeted resources will go.
The drawback to the lighter touch in analysis and documentation is a lack of hard data for all the various uses to which such data can be applied. But there is a substantial savings in the time necessary to accomplish something. The trick is to minimize the measurements and documentation without sacrificing any validity as a result." (Continued via Occupational Hazards, William Kincaid) [Ergonomics Resources]