In both the General Schedule (GS) and Federal Wage System (FWS), types of work are grouped together based on similar functions, skills and knowledge.
In the General Schedule, related occupations are organized numerically into Occupational Groups within the same multiple of 100. The occupations perform similar work and have similar sets of responsibilities.
In the Federal Wage System, occupations are grouped into Job Families, which are related in one or more ways: similar work functions, similar materials or equipment worked on, transferable skills and knowledge among occupations.
OPM Handbook of Occupational Groups and Families
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