Schedule Estimating Software

We have customer requests for enhancements to our legacy system all the time. The customer first needs an estimate as to how long it will take to develop, and thus how much it will cost. The way we respond is that we first try to figure out what it is exactly that the customer wants.

Then we get experts to think about a type of design in their mind. Once such a design has some meat, we will try to count up all the parts it will take to implement that design. This includes different GUI screens, interfaces, database code, and so on.

Once we know the pieces of the implementation, we decide to quantify them and rank them as being easy/medium/hard. Then we plug in how experenced the resources are that will implement the solution. This all goes into an Excel spreadsheet that has some smarts built into it. The result is a number of hours it will take for software completion.

Wouldn't it be easier if we did not have to rely on the experts to do all this analysis? I would like to send a business developer out to the customer, and have them be able to quickly estimate what the work is going to cost. We need something like Software Schedule Estimator for this job.