1 Scope
This document defines the charging performance metrics to be used during the evaluation or on-going monitoring of an electronic fee collection (EFC) system and the examination framework for the
measurement of these metrics.
It specifies a method for the specification and documentation of a specific examination framework which can be used by the responsible entity to evaluate charging performance for
a particular information exchange interface or for overall charging performance within
a toll scheme.
The following scheme types are within the scope of this document:
-
a) discrete schemes;
-
b) continuous schemes (autonomous type of systems).
This document defines measurements only on standardized interfaces.
This document defines metrics for the charging performance of EFC systems in terms
of the level of errors associated with charging computation.
This document describes a set of metrics with definitions, principles and formulations,
which together make up a reference framework for the establishment of requirements
for EFC systems and the subsequent examination of charging performance.
This document defines metrics for the following information exchanges:
-
—
charge reports (including usage evidence);
-
—
toll declarations;
-
— exception lists;
-
—
billing details and associated event data;
-
—
payment claims on the level of service user accounts;
-
— end-to-end metrics which assess the overall performance of the charging process.
These metrics focus solely on the outcome of the charging process, i.e. the amount
charged in relation to a pre-measured or theoretically correct amount, rather than
intermediate variables from various components as sensors, such as positioning accuracy,
signal range or optical resolution. This approach ensures comparable results for each
metric in all relevant situations.
The following aspects are outside the scope of this document.
-
— Definition of specific numeric performance bounds, or average or worst-case error
bounds in percentage or monetary units.
-
— Specification of a common reference system which would be required for comparison
of performance between systems.
-
— Measurements on proprietary interfaces.
NOTE It is not possible to define standardized metrics on such system properties. Neither
is it possible to define metrics for parts of the charging processing chain which
are considered to be the internal matter of an interoperability partner, such as:
— equipment performance, e.g. for on-board equipment (OBE), roadside equipment (RSE)
or data centres such as signal range, optical resolution or computing system availability;
— position performance metrics: the quality of data generated by position sensors
is considered as an internal aspect of the GNSS front end. It is masked by correction algorithms, filtering, inferring of data and the robustness
of the charge object recognition algorithms.
-
— The evaluation of the expected performance of a system based on modelling and measured data from
a trial at another place.