Fallback and Recovery Specification (FRS)

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DG TAXUD – EXCISE COMPUTERISATION PROJECT REF: ECP2-FITSDEV2-SC03-FRS FALLBACK AND RECOVERY SPECIFICATION (FRS) VERSION: 3.11-EN Exceptions typology 3 Exceptions typology This chapter contains a general description of the categories of exceptions and of the common characteristics of these categories. This categorisation has been the main guideline to discover exceptions throughout the analysis of the process flows. These exceptions are listed in Appendix A where they are presented along with the response scenarios that eventually allow restoring the good functioning of the system. The main categories are based on the origin and place of occurrence of these exceptions, namely: � Information Exchange; or � Processing. Although useful to systematically analyse the process flows to detect exceptions, these categories have not been found relevant in deeper analysis. 3.1 Information Exchange exceptions All information exchanges are subject to the same types of exception, regardless of the business context in which information has to be exchanged. Regardless of the scope (national or international) of an information exchange, or of the communication medium used (message exchanged through a communication network, paper based, phone, fax, e-mail...) exceptions happen at two levels: � Physical: failure of the communication medium itself, or loss of the information to be exchanged; � Semantic: the content of the information exchange does not have any business signification to the receiver. Whatever its level, an exception will have the same functional result: a failure of the information exchange. Note that most possible exceptions listed in this section are actually detected by the business process that receives and verifies information, in particular paragraph 3.1.2 „Exceptions at semantic level‟. However, as they apply to the information itself, we preferred keeping them in this section. 3.1.1 Exceptions at physical level 3.1.1.1 Unavailability of the communication medium Most generally, if the normal communication medium fails, information cannot be exchanged through normal EMCS procedures. However, for some exchanges, it has been found important to define alternate communication channels, either because the normal channel is felt particularly fragile or because the permanence of the exchange is essential for the good functioning of EMCS. ECP2-FITSDEV2-SC03-FRSv3.11.doc Page 20 of 53
DG TAXUD – EXCISE COMPUTERISATION PROJECT REF: ECP2-FITSDEV2-SC03-FRS FALLBACK AND RECOVERY SPECIFICATION (FRS) VERSION: 3.11-EN Exceptions typology 3.1.1.2 Loss of information to be exchanged For some reason, the addressee never receives the contents of an information exchange. If this is the case, different situations must be considered: 1. The lost information was expected. The addressee expects to receive certain information within a given time limit, and this information is lost: this is typically the case if information is exchanged in response to another information exchange. For example, if the report of receipt of an e-AAD does not arrive in due time. Most generally, but not always, such missing information is automatically detected through a timer or equivalent mechanism. 2. A response to the lost information was expected. If the lost information was not expected from the addressee, but the sender expects to receive a specific response to this information exchange within a certain delay. This situation is similar to the situation described in the example above, except that, in this case, it is the initial information exchange that is lost (in this example: the e-AAD never reached the consignee), instead of its response; that is to say that the e-AAD itself is lost. The result will be the same: the consignor will not receive the expected report of receipt. 3. The lost information was not expected. If the lost information was not expected from the addressee, and the sender does not expect to receive a specific response to this information exchange, the exception remains undetected until the lost information becomes needed. 3.1.2 Exceptions at semantic level Several defects are capable of making it impossible for the receiver of an information exchange to understand the business signification of the received information; typically: � the message refers to an object that is not known to the receiver; � the content of the received information is not consistent with already known information (e.g. a report of receipt is received from an economic operator who is not the consignee of the e-AAD). 3.1.2.1 Unknown object The typical case of unknown object is where a received information exchange refers to an ARC that is not known to the receiver. This results from a preceding error (the e-AAD did not reach the receiver), from a mistake (wrong ARC has been input) or from a fraud (use of a forged ARC). Similar cases are where a complementary submission of a control report or of an event report refers to a non-existent report identifier or where a response to a request refers to a non-existent correlation id. ECP2-FITSDEV2-SC03-FRSv3.11.doc Page 21 of 53
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Fallback and Recovery Specification (FRS)

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