cost estimation in software development project, Function Points?

Question

I have this quick question regarding cost estimation using Function Points.

We are doing a small (course project) project for a small company and it's for free, of course. Our instructor wants us to provide a cost estimate of the project using Function Points.

Computing the Function Points is somewhat straight forward (sort of).

Our problem now is on deriving other values (metrics) e.g. length of project duration, rate for the cost of the project per function points.

Obviously, we don't have historical data to based our estimate on. Is there some sort of "typical" cost per function point that we could follow out there? Please help.

Answer 1

Here are some formulas that Capers Jones devised from relatively high number of counted projects:

Given you have your FP count you can determine :

• Schedule in calendar months: FP^0.4
• Defect potential: FP^1.25
• Software development staffing levels: FP/150

You might go for industry standards for your technology to obtain FP/Person Months or Hours/FP if you don't have historical data (which is your case).

Answer 2

Software Engineering by Hans van Vleet quotes that one function point is 100 lines of COBOL (!), if that's any good to you. There's data out there for converting lines of code to staff-months, project duration, etc.

Do you have access to a library? Start with a general book on software engineering, or one of Steve McConnell's various books. They will contain data, and references to more data.

• Rapid Development
• Code Complete 2
• I mustn't forget Software Estimation. Personally I haven't yet read it that, but his other books are excellent.

Be aware that tracking progress and controlling the project scope are probably at least as important to success as the original estimate.

Answer 3

A simple GOOGLE will give you MANY results to start from

• Cost estimation in software engineering
• Handbook for Software Cost Estimation