This is because government now has thousands of mission systems using legacy architecture, each built for a single purpose to support the needs of a single program or agency. Common standards, common definitions of like data, or enterprise approaches are rarely used in the federal government. Government does not often leverage IT to make things simpler, generate economies of scale, or increase collaboration. Over the last 20 years, mission systems have become more customized and focused on single programs or needs, making government information systems at once more siloed and complex.