It has been estimated that 80% of all datasets include geographic references. Since these data often factor into preparing important decisions, we can assume that a significant proportion of all decisions have a geospatial aspect to them. Therefore, spatial decision support is an intrinsic component of societal decision-making. It is thus necessary for current and aspiring analysts, and for decision-makers and other stakeholders, to understand the fundamental concepts, techniques, and challenges of spatial decision support. This GIS&T topic explores the unique nature and basic concepts of spatial decision support, discusses the relationship between Spatial Decision Support Systems (SDSS) and Geographic Information Systems (GIS), and briefly introduces Multi-Criteria Decision Analysis (MCDA) as a decision support technique. The impact of Web-based and mobile information technology, ever-increasing accessibility of geospatial data, and participatory approaches to decision-making are touched upon and additional resources for further reading provided.
In this article, return on investment (ROI) calculations are applied to analyzing the current costs and financial benefits of geographic information systems (GIS) as a GIS management tool. How to develop GIS ROI methodologies to document the current financial value of GIS operations, as well as an outline of a ROI research design without and without GIS, are also included. Before the development and widespread use of GIS by government agencies and private enterprises, maps provided benefits and value to society. Early attempts to catalog the societal and financial benefits from mapping include examples related to geological mapping. An ROI analysis calculates the financial values of all the inputs into a system and all the outputs from the system, and then calculates the differences in value of the inputs and outputs. A key challenge to the growth of the emerging geospatial technology industry was to convince agencies and companies that GIS provided both societal and financial benefits. Companies and agencies often used benefit-cost analysis as a decision support tool when deciding to invest in GIS. But usually there was no effort or requirement by agencies to prove the ROI achieved after a project was completed and put into operation.