This section provides more detailed information and definitions on the five Data and Transactional Functions. Before getting into the details of the five functions there are several terms that you need to understand, because they'll be used in each of the subsequent definitions. These are taken directly from the CPM.
User identifiable
This term refers to defined requirements for processes and/or groups of
data that are agreed upon, and understood by, both the users and
software developers.
Control information
This is data that influences and elementary process of the application
being counted. It specifies what, when, or how data is to be processed.
Elementary process
An elementary process is the smallest unit of activity that is
meaningful to the user. An elementary process must be self-contained and
leave the business of the application being counted in a consistent
state.
Data Element Type, or DET
A data element type is a unique, user recognizable, non-repeated field.
This definition applies to both analyses of data functions and
transactional functions.
Record Element Type, or RET
A record element type is a user recognizable subgroup of data elements
within an Internal Logical File or External Interface File.
Data Functions - Internal Logical Files
(ILFs)
Data Functions - External Interface Files
(EIFs)
Transaction Functions - External Inputs
(EI's)
Transaction Functions - External Outputs
(EO's)
Transaction Functions - External Inquiries
(EQ's)
Summary