Disadvantages of using a geographic information system, or GIS, are that its technical nature might portray results as being more reliable than they actually are, and errors and assumptions can be hidden, leading to a lack of questioning into the results. Another disadvantage of analyzing the results from a GIS is that the results will only be as accurate as the data that they come from. Because of this, the data may not be able to serve different contexts, particularly if the data is not applicable.
For instance, if the input data on a GIS is entered at the county level, the results in the GIS will only be usable for the county level, not any other level, such as the district or ward levels. Data availability, in itself, is also a major issue. If the data is not available, than the GIS system is useless.
Furthermore, GIS systems are not like other programs. They do not come"off the shelf," which means that they must be assembled and constructed to a user design. This could be a long, complex and costly process. Because of this, many GIS systems don't come to fruition or fail outright in their implementation because their creation was rushed or inadequately planned.
GIS systems are often so complex, in fact, that it becomes difficult to describe the intangible benefits they may provide, making it difficult to find funding for their creation. Also, the technology behind GIS technology expands rapidly, causing GIS systems to have a high rate of obsolescence. It's also very difficult to make GIS programs that are both fast and user friendly. GIS systems typically require complex command language. Data fields and their accessibility are also not very understood, and data can become incomplete, obsolete or erroneous, rendering the GIS misleading.