Data functions represent the functionality provided to the
user to
meet internal and external data requirements. Data functions are
either internal logical files or external interface files.
-
An
internal logical file (ILF)
is a user identifiable group of logically related data
or control
information maintained within the boundary of the application. The
primary intent of an
ILF
is to hold data maintained through one or more
elementary processes
of the application being counted.
-
An
external interface file (EIF)
is a user identifiable group of logically related data
or control
information referenced by the application, but maintained within the
boundary of another application. The primary intent of an
EIF
is to hold data referenced through one or more
elementary processes
within the boundary of the application counted. This means an
EIF
counted for an application must be in an
ILF
in another application.
Source:
Function Point Counting Practices Manual
, see the IFPUG web site at
http://www.ifpug.org
for additional information.