1. A method for controlling security of data elements which represent an industrial process and which are manipulated by a plurality of users on a data processing system, said industrial process comprising a plurality of industrial process steps, said data security method comprising the steps of: assigning predetermined groups of said plurality of users to access predetermined groups of said data elements at predetermined ones of said industrial process steps; accepting a request from a user to access a data element; and preventing the access requesting user from accessing the requested data element if the access requesting user is not a member of one of said predetermined groups of said users which has been assigned access to a predetermined group of data elements which includes the requested data element or if the industrial process is not at an industrial process step corresponding to said predetermined ones of said industrial process steps; wherein said assigning step comprises the steps of: providing a first table executing on said data processing system, which maps said predetermined groups of users to corresponding security categories; providing a second table executing on said data processing system, which maps said plurality of industrial process steps to at least one old security category and to a corresponding at least one new security category; and in response to operator input, entering into said first and second tables user groups, industrial process steps and corresponding old and new security categories.