Every transmission
from one application to another is a potential point-of-failure,
and every atomic processing activity in an application is a potential
point of failure.
When a file is sent
from one trading partner's computer to another trading partner's
computer, via a point-to-point connection or via a third party
service provider, the receiving gateway should send back a business
signal called a Receipt
Acknowledgment in order to indicate that the sent document
was received. Most Receipt Acknowledgments indicate
success - successful receipt and successful validation. A
Receipt Acknowledgment is also sent of the document was received
but failed validation. A Receipt Acknowledgment does not
report other failures that may occur. The received document
may fail in such a way that a Receipt Acknowledgment cannot be
generated. Likewise, a sent document may fail mapping/translation
after a Receipt Acknowledgment has been sent, or the document
may fail the receiving application's edits. The Receipt
Acknowledgment itself may fail validation at the recipient's
gateway (the sender of the original document that is the subject
of the Receipt Acknowledgment).
Most standards provide
for automated exception notices that can be used to report the
failures that the Receipt Acknowledgment does not cover. However,
adding automated exception notices to the processing increases
the number of possible points of failure, because now the exception
notices themselves may fail transmission, compliance checking
or application edits. It is therefore recommended that
when business
signals (such as Receipt Acknowledgments) fail, or when
exception notices fail, the resolution should be handled manually
- via telephone or non-structured e-mail - in order to avoid
getting into an unending loop of sending exception notices to
report failures of exception notices or business signals.
| Step |
Description |
| This represents a typical
method for transmission tracking and error handling. Specifics
for different standards vary. |
| A. |
At start state A, the requesting
party and the responding party have a pre-established relationship.
The requesting party is ready to send a request. |
| 1. |
The requesting partner generates a request message.
It is assumed that the back-end application used has its own
transmission tracking and error handling logic.
|
| 2. |
The back-end application sends the
request message to the gateway. Generally, an intranet
or other internal network is used for the routing. |
| 3. |
If the send fails, the back-end
application should generate an exception notice or other error
message. This is done internally and should not impact
the trading partner. |
| B. |
At end state B, the outbound request
message has failed and the process ends. The problem will
have to be resolved and then the process re-started. |
| 4. |
If the send is successful, the requesting
party's gateway receives the request message. |
| 5. |
The back-end application may be
generating a proprietary format or a standard format.
The gateway translates the request message from the format generated
by the back-end application to the format expected by the recipient.
This could be any of several content standards, including X12,
EDIFACT, RosettaNet XML, OAGIS XML, etc. |
| 6. |
If the translation fails, the requesting
party's gateway should generate an exception notice or other
error message. This is done internally and should not
impact the trading partner. Whether or not the exception
gets sent to the back-end application depends on the organization's
support model. In this example, the exception notice is
not sent to the back-end application because front-line support
is handled by gateway personnel. |
| C. |
At end state C, the translation
or the transmission has failed. The problem needs to be
corrected and the process restarted. |
| 7. |
If the translation is successful,
the gateway envelopes the message according to what transport
and routing method will be used. |
| 8. |
The message is transmitted.
The two most common communications methods used are Value-Added
Networks and internet communications. |
| 9. |
The requesting partner's gateway
will monitor the status of the message to see if a Receipt Acknowledgment
has been received from the responding party's gateway. |
| 10. |
If the send is successful, the responding
party's gateway receives the request message. |
| 11. |
The responding party's gateway runs
a validation process to see if the request message is in compliance
with the chosen standard. |
| 12. |
If the validation generates a fatal
error - an error that makes it impossible for the gateway software
to generate a Receipt Acknowledgment, the responding party's
gateway may generate and send an exception notice. While
many standards recommend this approach, it is more common to
deal with this type of error manually. Note that error
checking for the send is not included on the diagram, but the
process is the same as for any other sent message. See
steps 8 and 9 above. |
| 13. |
The requesting party's gateway processes
the exception notice. If the exception notice fails, the
resolution should be handled manually. |
| D. |
At end state D, an exception has
been processed, and the process ends. The problem needs
to be corrected and the process restarted. |
| 14. |
If the Receipt Acknowledgment is
overdue and no exception notice has been received (manually
or electronically), the requesting party's gateway may generate
and send an exception notice to the responding party.
Note that error checking for the send is not included on the
diagram, but the process is the same as for any other sent message.
See steps 8 and 9 above. |
| 15. |
The responding party's gateway processes
the exception notice. If the exception notice fails, the
resolution should be handled manually. |
| E. |
At end state E, an exception has
been processed, and the process ends. The problem needs
to be corrected and the process restarted. |
| 16. |
If the validation step ends normally
(no fatal error), the responding partner's gateway sends a Receipt
Acknowledgment to the requesting partner's gateway.
Note that error checking for the send is not included on the
diagram, but the process is the same as for any other sent message.
See steps 8 and 9 above. |
| 17. |
The requesting party's gateway processes
the Receipt Acknowledgment. |
| F. |
At end state F, the
Receipt Acknowledgment has been processed, and indicates that
the request message passed validation. |
| 18. |
If the receipt acknowledgment indicates
that the requesting message failed validation, the requesting
party's gateway generates and sends an exception notice to its
back-end application. Whether or not the exception gets
sent to the back-end application depends on the organization's
support model. In this example, the exception notice is
sent to the back-end application because front-line support
is handled by back-end application support personnel.
Note that error checking for the send is not included on the
diagram, but the process is the same as for any other sent message.
See steps 8 and 9 above. |
| 19. |
The requesting party's back-end
application processes the exception notice. If the exception
notice fails, the resolution should be handled manually. |