How much a variable contributed to the result of some cost function

Question

I have this simple cost function: $\sum_{i=1}^n d_i\times h_i \times a_i$

I wanted to analyze, for example, how much the $a$ component/variable contributed to the final cost function. In other words, i'm looking for some expression that tells me if the $a$ variable produced a big impact in the final cost or not.

What is the best and most straighforward way to achieve this? Thank you in advance.

Answer 1

To answer my question:

$C_d = \sum_{i=1}^n d_i$

$C_h = \sum_{i=1}^n (d_i \times h_i - di)$

$C_a = \sum_{i=1}^n (d_i \times h_i \times a_i - d_i \times h_i)$

$C_t = C_d + C_h + C_a$