Don't Guess, Solve it!

Algebra Level 3

If \(a, b, c\) are the sides of a triangle, then find the minimum value of the expression \[\frac { a }{ c+a-b } +\frac { b }{ a+b-c } +\frac { c }{ b+c-a } .\]

(This question is a modification of the one that appeared in RMO 1999)