Introduction to SoftwareEstimation

Estimation is done in terms of* Size*Effort* Schedule* Cost

Size estimate: This is thefirst estimation task. A measurement that tells the user what the system shalldo. Size estimate is usually done by Function Points Analysis, Feature points,Use Case points or Lines of Code (LOC).
Effortestimate: The estimate for the manpower that is requiredfor a project. This is a most important factor determines many crucialdecisions.Measured in terms of : person-hours, person-days,person-months, etc.

The popular effort estimation methods are:
size=2>* COCOMO 81
* COCOMO II
* Putnam’s Software Equation
*Felix-Watson
* Bailey-Basili

Example: If requirement is to build a web based system withLogin mechanism. The Size Estimate in terms of LOC may come to 150 Lines, andEffort estimate would be 8 person hours. Hence Effort estimate isdependent on size estimate.

Schedule estimate: Thisis the duration between the start of the project and the end of the projectOften effort estimate are revised to meet the customer imposed scheduleRepresented in terms of : Calendar-months, calendar-days, weeks, etc.

Cost estimate: A major driver of cost estimation is the manpower cost (based on the estimatedeffort).
Other costs include : travel, communication, facilities, projectspecific training , hardware and software costs for the project team, etc.

High Quality & Productivity (Q&P) reduce the cost and minimize theschedule of a project. Q&P are the twin aims of a project. Hgh Q&P canbe maintained by employing good processes.