Disadvantages of function point analysis.1. It needs subjective evaluations with a lot of judgement involved.
2. Many effort and cost models are based on LOC, so function points need to be converted.
3. Less research data is available on function points as compared to LOC.
4. It is performed after creation of design specifications.
5. It has low accuracy of evaluating as a subjective judgement is involved.
6. As the learning curve is quite long its not easy to gain profiency.
7. It is a time consuming method.