**5. Assessment of Infrastructure**

As a crucial step for assessing the infrastructure, transformers' heal index should be assessed accurately by some standards and scoring system. Technical condition and their standards should cover their general status [28]. The technical and operational conditions are mentioned below:

	- 1. Transformer Parallelism Index
	- 2. Transformer Reserve Index
	- 3. Transformer Rated Power
	- 1. Main Health Index (HIm)
	- 2. Insulating Paper Health Index (HIiso)
	- 3. DGA Health Index (HICH)
	- 4. Oil Health Index (HIoil)

In this section of the paper, mentioned index is explained briefly.

*5.1. Technical Conditions*
