This chapter discusses how a simple Geographic Information System (GIS) desktop application becomes an enterprise system. GIS professionals, users, and developers need to understand that a successful enterprise system has a strategic vision. The professionals of GIS can incorporate and use the ideals of enterprise architecture to improve and enhance the value of their enterprise systems. The chapter deals with an examination of various sources. The Environmental Systems Research Institute (ESRI) is a company that produces the ArcGIS suite, which has become the software standard for GIS. ESRI’s software applications have become the standard for GIS software and definitions; the GIS community readily accepts practices. People in government, industry, and academia have wondered about the number of similar yet, different definitions of what is an enterprise GIS. Medina County Health Department environmental division required a GIS for tracking mosquito response, sanitary concerns, and problem septic systems.