Customs Declaration Processing System Detailed User and ...

DETAILED USER & TECHNICAL REQUIREMENTS FOR CDPS
AND USE-CASE MODELS
Ref: PHASE V
Internet providers. In addition to the existing communication links (optical cables of
Macedonian railway and Ministry of Interior Affairs, ADSL by Macedonian Telekom), the
introduction of a second broadband access to the Internet will become even more feasible and
economically justified with the near-future introduction of the WiMAX broadband service. For
security reasons, every Customs Office needs to be connected to the MCA Headquarters and
thus the central installation of CDPS via a VPN which uses IPSec tunnelling mode. The use of
two independent Internet providers significantly reduces the probability of loss of connection
between COs and HQ. Short-period losses of communication links from one Internet provider
shall have no impact on the CDPS operations and shall not be noticed by the end users.
Additional costs due to the existence of redundant communication links between COs and HQ
will be more than compensated by the increased overall reliability of CDPS, and improved user
experience and satisfaction. However, this method only affects the communications
infrastructure, but does not add any additional technical or functional requirements for CDPS.
Hence it does not increase the licensing and customisation costs for CDPS
• Paper-based fall-back procedures: Fallback and recovery procedures must be also foreseen in
order to minimise the period of the CDPS central installation unavailability. For the IT services
which are considered to be time critical, organisational fallback solutions (alias Business
continuity plan) must be defined and supported eventually by legislation. In the very rare cases
where both communications links between a BCO and HQ are down for a significant period of
time which is long enough to influence the normal operations of a BCO, a paper-based
procedure needs to be at disposal to the customs officers. After the communications links have
been restored, CDPS shall allow the end–users to enter the data from the paper-based procedure.
• Offline working mode: Due to the high-availability requirement for CDPS, in [R17] we
elaborated on the existence of an offline working mode for the BCOs with non-reliable
communication links to the CDPS installation at the MCA HQ. A cut-down version of CDPS
needs to be installed on a local server at each BCO. The local version of CDPS will implement
only the functionality which is absolutely necessary to allow BCOs to continue the normal
operations during the brief periods of lost connection to MCA HQ. In the online mode, the
central server installation of CDPS is used over the Internet. For the off-line mode, a cut-down
local installation of CDPS with Oracle DB personal edition is used. The offline mode can be
used when an Internet access is not available. When in offline mode, CDPS still supports
multiple users (from the same border crossing office). When the connection to the HQ is
restored after a period of lost connection, the local copy of the database needs to synchronise
with the central copy. This is a two-directional merge-type synchronisation. Synchronisation
should be done as soon as possible in order to minimise the number of conflicts. However, data
replication, data synchronisation, shared data ownership between BCOs and HQ, and the need
for multiple installations of CDPS can significantly increase the development/customisation
costs of CDPS, the maintenance costs of CDPS, and the architectural complexity of CDPS.
Taking into account the advantages and drawbacks of the above three methods, with the aim to
increase the reliability and availability of CDPS it is our recommendation to implement the first two
methods only, namely: Redundant communication lines and Paper-based fall-back procedures. It is
estimated that the additional costs for an offline working mode related to software development,
customisation and maintenance will significantly outweigh the benefits in the form of increased
availability.
5.2.4.2 Requirements
In order to ensure a proper handling of messages during downtimes, the necessary precautions have
to be taken.
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