This paper reports on a case study of work analysis using geospatial intelligence technology conducted on a manufacturing line at a Denso plant in FY2021. First, the work site targeted in this case study, the purpose of the analysis, and the data measured and collected at the work site are outlined. Next, we describe the generation of a work area transition model using indoor positioning data and the clustering of the work area transition instances for the purpose of analyzing work patterns. The results of the clustering are compared with the roles of each worker, and the analysis of unexpected work patterns is also reported.