Software Engineering: Function Point Analysis: Transactional FPs

Intro Counting Data FPs Transactional FPs Estimation

Each screen, form, dialog box, report, or diagram corresponds to one (or more if it performs more than one function) EI, EO, or EQ, if it also references at least one file and performs one function.

External Inputs (EI)

External input is an "elementary process that processes data or control information that enters from outside the boundary of the application." The data may alter an ILF and/or alter the behavior of the system. Control information must have a business meaning (eg, not navigation actions, not login or startup operations, not refreshing, not clicking to move data, ...).

Complexity of each EI is computed from

External Outputs. (EO)

"An External Output (EO) is an elementary process that generates data or control information that exits the boundary of the application." There must be processing logic which contains at least one calculation, creates derived data, maintains one or more ILFs, or alters the system in some way. Rearranging, sorting, or reformatting data is not considered an EO, neither are error messages or confirmations considered an EO.

Complexity measurement requires computing DET and FTR values.

External Inquiries. (EQ)

External Inquires (EQ) simply present data from an ILF or EIF without calculation or changing an ILF. For example, viewing or browsing data or reading email would be an EQ. In addition, using list boxes or pointing and clicking on something to return unprocessed data is an EI.
Complexity. Count DETs and FTRs as for the EO. Use the same complexity matrix as EO.

Complexity matrixes

EI Complexity
<2LowLow Avg
2 LowAvgHigh
>2AvgHigh High
EO and EQ Complexity
<2LowLow Avg
2-3 LowAvg High