Visual Six Sigma: Making Data Analysis Lean

Chapter 4. Reducing Hospital Late Charge Incidents

This case study is set early in the deployment of a Lean Six Sigma initiative at a community hospital. A master black belt by the name of Alex Griffin was hired to help support the Lean Six Sigma effort. Management identified the billing department, and in particular late charges, as an area that tied up millions of dollars per year, and hence an area badly in need of improvement. This case study describes how Alex and Alice Griffith, an associate in the billing department, analyze billing data in order to define project opportunities for green belt teams.

The case study is almost entirely embedded in the Uncover Relationships stage of the Visual Six Sigma Data Analysis Process introduced in Chapter 2 (Exhibit 2.3). Alex and Alice are detectives, searching for clues that might explain the large number of late charges. Their work encompasses a number of the How-We-Do-It techniques described under Uncovering Relationships in Exhibit 3.30. Their findings will initiate the work of project teams; these teams will work through all six of the stages of the Visual Six Sigma Data Analysis Process.

In this case study, Alex and Alice analyze the late charge data for January 2008. The data set consists of 2,032 records with late charges. The columns include both nominal and continuous variables, as well as dates. Alex and Alice visualize their data using histograms, bar graphs, Pareto plots, control charts, scatterplots, mosaic plots, and ...