Transactional functions represent the functionality provided
to the
user to process data. Transactional functions are either external
inputs, external outputs, or external inquiries.
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An
external input (EI)
is
an elementary process that processes data or control information
that comes from outside the applications
boundary. The primary intent of an
EI
is to maintain one or more
ILF
s and/or to alter the behavior of the system.
-
An
external output (EO)
is an elementary process that sends data or control
information
outside the applications
boundary. The primary intent of an external output is to present
information to a user through processing logic other than or in
addition to the retrieval of data or control information. The
processing logic must contain at least one mathematical formula or
calculation, or create derived data. An external output
may also
maintain one or more
ILF
s and/or alter the behavior of the system.
-
An
external inquiry (EQ)
is an elementary process that sends data or control
information
outside the application boundary. The primary intent of an external
inquiry is to present information to a user through the retrieval of
data or control information. The processing logic contains no
mathematical formula or calculation, and creates no
derived data. No
ILF
is maintained during the processing, nor is the behavior
of the
system altered.
Source:
Function Point Counting Practices Manual
, see the IFPUG web site at
http://www.ifpug.org
for additional information.