Subject: Software Engineering

Topic: Matrics for Process & Projects

Difficulty: High

It has been surveyed that nearly one-third projects overrun their budget and late delivered and two-thirds of all major projects substantially overrun their original estimates. The accurate prediction of software development costs is a critical issue to make the good management decisions and accurately determining how much effort and time a project required for both project managers as well as system analysts and developers. ; software project personnel can not tell managers and customers that their proposed budget and schedule are unrealistic. This may lead to optimistic over promising on software development and the inevitable overruns and performance compromises as a consequence. But, actually huge overruns resulting from inaccurate estimates are believed to occur frequently.

The overall process of developing a cost estimate for software is not different from the process for estimating any other element of cost. There are, however, aspects of the process that are peculiar to software estimating. Software cost estimation is a continuing activity which starts at the proposal stage and continues through the lift time of a project. Cost estimation is one of the most challenging tasks in project management. It is to accurately estimate needed resources and required schedules for software development projects. The software estimation process includes estimating the size of the software product to be produced, estimating the effort required, developing preliminary project schedules, and finally, estimating overall cost of the project.

To provide a sufficiently broad communication bandwidth for the experts to exchange the volume of information necessary to calibrate their estimates with those of the other experts, a wide-band Delphi technique .The estimating steps using this method:

-Coordinator present each expert with a specification and an estimation form.

• Coordinator calls a group meeting in which the experts discuss estimation issues with the coordinator and each other.

• Experts fill out forms anonymously

• Coordinator prepares and distributes a summary of the estimation on an iteration form.

The advantages of this method are:

• The experts can factor in differences between past project experience and requirements of the proposed project.

• The experts can factor in project impacts caused by new technologies, architectures, applications and languages involved in the future project and can also factor in exceptional personnel characteristics and interactions, etc.