Over the last three decades many multigroup indexes have been developed and applied to occupational and school segregation in both time series and cross-sectional studies. In this paper, by reference to the properties of two well-known segregation indexes, we contrast the features of a systems based methodology to analyse time series changes in occupational segregation by gender/race with an approach based on the disaggregation of gender/race groups through the derivation of local indexes. We conclude that the systems based approach is superior and illustrate our claim via an empirical study of US employment data defined across Gender, Race and Occupation for the years 2010 and 2018.