There are a variety of point estimators, each with different properties. The MAP estimator has good asymptotic properties, even for many difficult problems, on which the maximum-likelihood estimator has difficulties. For regular problems, where the maximum-likelihood estimator is consistent, the function point estimation pdf-likelihood estimator ultimately agrees with the MAP estimator.
An inconsistent maximum likelihood estimate”. This page was last edited on 23 February 2017, at 15:26. A functional size measurement method. 1 functional size measurement method.
IFPUG functional size measurement method. NESMA function size measurement method version 2. Once the function is identified and categorized into a type, it is then assessed for complexity and assigned a number of function points. Each of these functional user requirements maps to an end-user business function, such as a data entry for an Input or a user query for an Inquiry. There is currently no ISO recognized FSM Method that includes algorithmic complexity in the sizing result.
Recently there have been different approaches proposed to deal with this perceived weakness, implemented in several commercial software products. This variation highlights computational function. Bang, defined as “the measure of true function to be delivered as perceived by the user. Bang measure may be helpful in evaluating a software unit’s value in terms of how much useful function it provides, although there is little evidence in the literature of such application.
Maintenance of Operational Systems—An Overview. This allows accounting for functions not readily perceivable by the user, but essential for proper operation. The risk of “inflation” of the created lines of code, and thus reducing the value of the measurement system, if developers are incentivized to be more productive. FP advocates refer to this as measuring the size of the solution instead of the size of the problem. Jones offers a method of correcting this in his work.
LOC measures are not useful during early project phases where estimating the number of lines of code that will be delivered is challenging. However, Function Points can be derived from requirements and therefore are useful in methods such as estimation by proxy. In addition, there have been multiple attempts to address perceived shortcomings with the measure by augmenting the counting regimen. Others have offered solutions to circumvent the challenges by developing alternative methods which create a proxy for the amount of functionality delivered. The Economics of Software Quality, Addison-Wesley, 2012.
Applied Software Measurement: Assuring Productivity and Quality. Function point analysis: difficulties and improvements. IEEE Transactions on Software Engineering. Function point analysis: evaluation of a software cost estimation model. European Journal of Information Systems. Jeffery, R and Stathis, J.