Sources of error in Finite Element Method

1. Discretization error: Its results from transforming the physical problem into a finite element model and can be related to modeling the boundary condition. These results are more prominent in 2D and 3D problems and can be reduced by increasing the number of elements to a sufficient extent.

2. Formulation error: It results from the use of elements that do not describe the behavior of the physical problem.

3. Numerical error: It includes truncation errors or round-off errors. A slight error due to round-off in one element is likely to result in appreciable error due to cumulative effect of these errors throughout the domain.

4. Human error: It results due to taking the wrong input data.