current_health {CNAIM}

Current Health score

Description

This function calculates the current health score for a given electric network asset (cf. CNAIM, 2021. Page 23, section 4.3.2).

Usage

current_health(
  initial_health_score,
  health_score_factor,
  health_score_cap = "Default",
  health_score_collar = "Default",
  reliability_factor = "Default"
)

Arguments

initial_health_score

Numeric. The output from the function initial_health().

health_score_factor

Numeric. E.g. output from the function health_score_excl_ehv_132kv_tf().

health_score_cap

Numeric. Specifies the maximum value of current health score. The cap is used in situations where a good result from a condition inspection or measurement implies that the health score should be no more than the specified value. The cap is derived as the minimum of the observed condition cap and the measured condition cap. Measured and observed condition caps are found in lookup tables depending in the asset category, when determine the observed and measured condition factors. A setting of "Default" sets the health_score_cap to 10.

health_score_collar

Numeric. Specifies the minimum value of Current Health Score. The collar is used in situations where a poor result from a condition inspection or measurement implies that the health score should be at least the specified value. The collar is derived as the minimum of the observed condition collar and the measured condition collar. Measured and observed condition collars are found in lookup tables depending in the asset category, when determine the observed and measured condition factors. A setting of "Default" sets the health_score_collar to 0.5.

reliability_factor

Numeric. reliability_factor shall have a value between 0.6 and 1.5. A setting of "Default" sets the reliability_factor to 1. See section 6.14 on page 73 in CNAIM (2021).

Value

Numeric. The Current health score.

Source

DNO Common Network Asset Indices Methodology (CNAIM), Health & Criticality - Version 2.1, 2021: https://www.ofgem.gov.uk/sites/default/files/docs/2021/04/dno_common_network_asset_indices_methodology_v2.1_final_01-04-2021.pdf

Examples

current_health(initial_health_score = 0.5,
              health_score_factor = 0.33,
              health_score_cap = 10,
              health_score_collar = 0.5,
              reliability_factor = 1)