Challenges in cost estimation.

• There is no exact science for cost estimation - it will never be considered as all accurate.

• No person can reasonably predict what can go wrong in the project.

• Most estimation methods assume things will proceed as expected and simply adds some slack to account for what can go wrong.

Possible solutions

• Delay estimation - 100% accuracy but less usefull

• Base estimation on data from previous projects that have been completed.

• Break the system to smaller parts and generate the estimates for smaller parts, which is easier.

• Use emperically-based estimation methods.