A business does not have a single, integrated system containing all its data for the whole of the organisation. Instead, the business has a number of information systems it uses for its operations. The business finds that if it has to update data for one system, it has to work out which other systems must also be updated with that same data. This is extra effort for staff in working out which other systems to update and in carrying out the updates. As a result of this, the data on different systems is unnecessarily repeated.

What is the term applied to such systems that this business has?