ABSTRACT
When a number of computer files are created and updated in such a way that each supports a single application, it is certain that many of the items of data appear in one form or another on several of the files. The solution provided by the common data base is that data is recorded and updated at one point only, and coded and controlled so that each item can be used to satisfy all the applications which make use of it. The situation can also arise where two groups in an organisation feel they have an equal right to supply the same data elements, and neither is prepared to accept that such data should be supplied and maintained by the other. In matters of salary administration and staff selection, personnel departments probably have more difficulty with data processing departments than with any other group.
