ATM/ANS.OR.A.085 Aeronautical data quality management

AERONAUTICAL DATA CATALOGUE The aeronautical data catalogue presents the scope of data that can be collected and maintained by the AIS providers and provides a common terminology that can be used by data originators and service providers.

GENERAL Minimum requirements for the processing of aeronautical data may be found in EUROCAE ED-76A, ‘Standards for Processing Aeronautical Data’, June 2015, which aims to assist aeronautical data chain actors.

RESOLUTION

(a)Stating that resolution needs to be commensurate with the actual accuracy means that digital data needs to have sufficient resolution to maintain accuracy. Typically, if an accuracy of .1 unit is needed, then a resolution of 0.01 or .001 units would enable a data chain to preserve the accuracy without issue. A finer resolution could be misleading as one could assume that it supports a finer accuracy. This factor range of 10 to 100 between accuracy and resolution is applicable regardless of the units of measurements used.

(b)The resolution should be enough to capture the accuracy of the data.

TRACEABILITY Traceability is supported by maintaining the metadata.

FORMAT The format requirements should be specified in the formal arrangements.

VALIDATION AND VERIFICATION

(a)The processes implemented to carry out validation and verification should define the means used to:

(a)verify received data and confirm that the data has been received without corruption;

(b)preserve data quality and ensure that stored data is protected from corruption; and

(c)confirm that originated data has not been corrupted prior to being stored.

(b)Those processes should define the:

(1)actions to be taken when data fails a verification or validation check; and

(2)tools required for the verification and validation process.

VALIDATION AND VERIFICATION — GENERAL

(a)Validation

(1)Validation is the activity where a data element is checked as having a value that is fully applicable to the identity ascribed to the data element, or where a set of data elements are checked as being acceptable for their intended use.

(2)The application of validation techniques considers the entire aeronautical data chain. This includes the validation performed by prior data chain participants and any requirements levied on the data supplier.

(3)Examples of validation techniques

(i)Validation by application One method of validation is to apply data under test conditions. In certain cases, this may not be practical. Validation by application is considered to be the most effective form of validation. For example, flight inspection of final approach segment data prior to publication can be used to ensure that the published data is acceptable.

(ii)Logical consistency Logical consistency validates by comparing two different data sets or elements and identifying inconsistencies between values based on operative rules (e.g. business rules).

(iii)Semantic consistency Semantic consistency validates by comparing data to an expected value or range of values for the data characteristics.

(iv)Validation by sampling Validation by sampling evaluates a representative sample of data and applies statistical analysis to determine the confidence in the data quality.

(b)Verification

(1)Verification is a process for checking the integrity of a data element whereby the data element is compared to another source, either from a different process or from a different point in the same process. While verification cannot ensure that the data is correct, it can be effective to ensure that the data has not been corrupted by the data process.

(2)The application of verification techniques considers only the portion of the aeronautical data chain controlled by the organisation. Yet, verification techniques may be applied at multiple phases of the data processing chain.

(3)Examples of verification techniques

(i)Feedback Feedback testing is the comparison between the output and input state of a data set.

(ii)Independent redundancy Independent redundancy testing involves processing the same data through two or more independent processes and comparing the data output of each process.

(iii)Update comparison Updated data can be compared to its previous version. This comparison can identify all data elements that have changed. The list of changed elements can then be compared to a similar list generated by the supplier. A problem can be detected if an element is identified as changed on one list and not on the other.

VALIDATION AND VERIFICATION TECHNIQUES Validation and verification techniques are employed throughout the data processing chain to ensure that the data meets the associated DQRs. More explanatory material may be found in Appendix C (Guidance on compliance with data processing requirements) to EUROCAE ED-76A ‘Standards for Processing Aeronautical Data’.

ELECTRONIC MEANS The transmission of aeronautical data and aeronautical information may be done by various electronic means.

FORMAL ARRANGEMENTS Formal arrangements should include the following minimum content:

(a)the aeronautical data to be provided;

(b)the data quality requirements (DQRs) for each data item supplied according to the aeronautical data catalogue;

(c)the method(s) for demonstrating that the data provided conforms with the specified requirements;

(d)the action to be taken in the event of discovery of a data error or inconsistency in any data provided;

(e)the following minimum criteria for notification of data changes:

(1)criteria for determining the timeliness of data provision based on the operational or safety significance of the change;

(2)any prior notice of expected changes; and

(3)the means to be adopted for notification;

(f)the party responsible for documenting data changes;

(g)data exchange details such as format or format change processes;

(h)any limitations on the use of data;

(i)requirements for the production of data origination quality reports;

(j)metadata to be provided; and

(k)contingency requirements concerning the continuity of data provision

FORMAL ARRAGNEMENTS ATM/ANS providers may use the predetermined template ‘Data Provision Agreement’ developed by EUROCONTROL (ADQ Formal Arrangement Template, version 1.1. issued on 22 February 2016.)

SOFTWARE

(a)A means by which the requirement in ATM/ANS.OR.A.085(i) can be met, is through the verification of software applied to a known executable version of the software in its target operating environment.

(b)The verification of software is a process of ensuring that the software meets the requirements for the specified application or intended use of the aeronautical data and aeronautical information.

(c)The verification of software is an evaluation of the output of an aeronautical data and/or aeronautical information software development process to ensure correctness and consistency with respect to the inputs and applicable software standards, rules and conventions used in that process.

TOOLS Tools can be qualified meeting point 2.4.5 Aeronautical Data Tool Qualification of EUROCAE ED-76A/RTCA DO-200B ‘Standards for Processing Aeronautical Data’, dated June 2015.

DATA ERROR DETECTION TECHNIQUES

(a)Digital error detection techniques can be used to detect errors during the transmission or storage of data. An example of a digital error detection technique is the use of cyclic redundancy checks (CRCs). Coding techniques can be effective regardless of the transmission media (e.g. computer disks, modem communication, or internet).

(b)Transmission of data via electronic/digital means (e.g. file transfer protocol (FTP) sites, web downloads, or email) may be subject to malicious attack that can corrupt the integrity of data for its intended use. Provision of means to mitigate the intentional corruption of digitally transmitted data may already exist within the organisational construct and operating procedures of participating entities.

(c)The objective of data security is to ensure that data is received from a known source and that there is no intentional corruption during processing and exchange of data.

(d)Records should be maintained to show what data security provisions have been implemented.

(e)Provisions supporting this objective may include:

(1)implementation of technical data security measures to provide authentication and prevent intentional corruption during exchange of data (e.g. secure hashes, secure transmissions, digital signatures); and

(2)implementation of organisational data security measures to protect processing resources and prevent intentional corruption during processing of data.

DATA ERROR PROCESSING More explanation and guidance may be found in Appendix C (Guidance on compliance with data processing requirements) to EUROCAE ED-76A.

ERROR HANDLING

(a)The term ‘error’ is understood as being defective, degraded, lost, misplaced or corrupted data elements, or data elements not meeting stated DQRs.

(b)Guidance on how to detect, identify, report and address/resolve aeronautical data errors may be found in Appendix C (Guidance on compliance with data processing requirements) to EUROCAE ED-76A ‘Standards for Processing Aeronautical Data’.