KPI021 | NOx efficiency V4.0

Key Performance Indicator

This KPI expresses the amount of NOx emitted relative to the transport work performed.

Interpretation	As the PI Value 'Emitted Mass NOx' is to be given in Kg, the figure is multiplied by 1 thousand to get the KPI value in g/transport work (ton mile, passenger mile, TEU mile, etc). Consumption of fuel in only the main engine should be accounted for, unless running on diesel (as the diesel engine's powers are distributed where needed and not directly related to the main engine only).
Notes	The issue of NOx efficiency is complicated by the fact that there are several influencing factors driving the fuel consumption. The commercial operator is responsible for utilization of the ship’s capacity hereby affecting the transport work. The other main factor regarding transport work is the market itself. Ship’s attributes such as hull design, engine type (and to some extent age) as well as the load factor for each voyage are all influencing the NOx efficiency through the amount of fuel burned.
Unit	g/[Cargo Unit] mile
Scope	Ship level
Calculation period	Quarterly

Formula

[formula]KPI021 = \frac {PI008} {PI064} \times 10^3[/formula]

PI064	Transport work
PI008	Emitted mass of NOx

Example

PI008	Emitted mass of NOx	= 4700000 kg
PI064	Transport work	= 20,710,647,000 ton mile
KPI Value	NOx efficiency	= 0.193

Ranking calculation example

Step 1: Calculate KPI value

PI008 Emitted mass of NOx = 4700000 kg

PI064 Transport work = 20710647000 [cargo unit] mile

Step 2: Calculate percentile rank by comparing KPI value against other ships with the same criteria. We assume that another 99 (100 in total) participate in the ranking with the same criteria and our ship has position 33 and you are the only ship in that rank.

Step 3: Calculate the percentile rank by capturing the count of all participant below your rank (cl). The frequency of ships in your same rank (fi). The total number of ships in the ranking segment (N).

[formula] KPI021_{Percentile Ranking} = \frac{cl+05*fi}{N} * 100 = \frac{67+0.5*1}{100} * 100 = 67.5 [/formula]

Interpretation: Based on the above example, we could say that, when it comes to , this ship belongs in the 67.50th percentile of the ships that are being compared with based on its ranking criteria in the respective quarter.