Explain how to estimate software development costs using the following approaches.

The two approaches I chose where the Constructive Cost Model (COCOMO), and the Function Point Analysis (FPA). Each contributes in its own way to providing estimates, and calculations necessary to complete a project.
The Constructive Cost Model (COCOMO) is an software cost estimation model developed by Barry W. Boehm. The model uses a basic regression formula with parameters that are taken from past current project information, as well as future project characteristics. This approach was first published in Boehm's 1981 book “Software Engineering Economics” as a model for estimating effort, cost, and schedule for software projects.
COCOMO measures a piece of software by counting the source lines of code (SLOC) in the final program. It requires that a work breakdown structure be done prior to the estimation work. The number of lines of code is then estimated for each of the units of the work breakdown structure. The approach provides guidelines for counting lines of code to encourage some standardization across projects and across organizations. COCOMO is defined in terms of three different models: * Basic model * Determines its estimates of required effort based primarily on your estimate of the software project's size. * Intermediate model * Provides much better estimates because you supply settings for 15 Cost Drivers that determine the effort, and duration of software projects. * Detailed model * Similar to the Intermediate model, but this model uses different Effort Multipliers for each stage of a project.
The Function Point Analysis (FPA) technique, originally developed by Alan Albrecht of IBM in the late 1970's, is a method of measuring software base off what the system would deliver to the user, rather than lines of code or other information system-related concerns. The function point count, a figure that is independent of the programming language, programming style, and the development process as a whole, is a metric that represents the relative size of a software system. One of the initial design criteria for function points was to provide a mechanism that both software developers and users could utilize to define functional requirements. It was determined that the best way to gain an understanding of the users' needs was to approach their problem from the perspective of how they view the results an automated system produces. Therefore, one of the primary goals of Function Point Analysis is to evaluate a system's capabilities from a user's point of view. To achieve this goal, the analysis is based upon the various ways users interact with computerized systems.
The basis of this paper was to give some insight on the different approaches used in software cost estimation and the way the methods are used as such. Both of the methods are widely use by present project managers and modified to meet the objective of the task it is used for. It is my sincere hope that the information I provided answers the question provide for this assignment.
Word Count: 495

Citations http://approachproject.com/component /k2/item/10-software-estimation-techniques.html
(Analysis of Software Cost Estimation using COCOMO II), International Journal of Scientific & Engineering Research Vol. 2, Issue 6, June 2011