Follow these guidelines when developing the workflow and user interface of a solution:
Make it clear to the user when document input is expected. Depending on the nature of the solution, a prompt asking the user to place a certain document on the scanner may be beneficial. Alternatively, if the purpose of the solution makes the expectation of document input obvious, a prompt may be unnecessary.
When possible, present all prompts before scanning the document. If a user does not know some of the information requested through prompts, then cancel the job before scanning since it takes the most time. On e-Task 2 or later printers, you may choose to present prompts or confirmation after scanning and partially processing the document when appropriate. On e-Task printers, however, no prompts can be used after the scan task.
Handle user-initiated cancels at all stages.
When possible, allow the user to batch process multiple documents. To avoid forcing the user to wait between scan tasks, scan and store all documents before processing and routing.
To avoid unexpected errors due to incorrect or missing input, validate documents to scan the correct documents and the correct number of documents or pages.
When possible, complete all prompting and scanning before beginning processing and routing. Again, on e-Task 2 or later printers, you may choose to present prompts or confirmation after scanning and partially processing the document when appropriate. Users do not expect a long wait between prompts, so minimize such intermediate processing.
After processing and routing, provide confirmation of success or failure to the user. On e-Task devices, confirmation must be printed, and no further action may be taken in case of failure. On e-Task 2 or later devices, you can use more prompts to deliver confirmation, and allow a user option to take corrective action in case of failure.
Report the percentage of completion to the system when the task is completed, or as accurately as possible when the task fails.
Handle all errors and recover whenever possible. On e-Task 2 or later devices, allow a user option to take corrective action in case of errors. For example, the user may be prompted to rescan a document when a bar code could not be read because it was scanned upside down. On e-Task devices, errors that occur during or after a scan can be reported only on the confirmation page.
Log all errors regardless of recovery ability, and report them to the user whenever possible. Log non-fatal errors at the “ERROR” level and fatal errors at the “FATAL” level.
Log potential problems that are not errors at the “WARN” level.
To save space in the log and maintain better system performance, log messages that only an administrator can see during normal operation at the “INFO” level. Remember that an administrator can see the overall completion status of a job without a log message using the Jobs task in Lexmark Management Console (LMC).
To determine the location of a bug, log messages at the “DEBUG” level. Messages at the “DEBUG” level are not recorded unless specifically enabled by an administrator, so these messages do not affect space and performance during normal operation.