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The following are a few guidelines we use when writing operational scripts:

•  All operational tasks should be rerunnable, or at the very least include instructions in the manual page on how to restart the task (e.g. by running another task first).
• Tasks should be able to run independently of the server (again the manual page should have instructions on how to restart on a different server).
• The critical parts of a suite should be independent as far as possible from the less critical parts. For instance, ECMWF keeps its operational archiving tasks in a separate family from the time-critical tasks.
•  You should be consistent in your use of scripts.
• You should turn on error failing so ecFlow can trap failures, e.g. using set -e and trap in ksh.
• You should not use UNIX aliases.
• You should not use shell functions, as these can cause problems trapping errors. (or explicitly repeat the trapping to ensure portability)
• Exported variables should be UPPERCASE.
• Defined ecFlow variables should not start with generated ECF_ to avoid confusion.
• All variables should be set (using default values if necessary).
• Try to avoid using NFS mounted file systems in the critical path.
•  Use files or file-systems owned by one single "operational" user
•  Always clean up. i.e. Job output, server logs, job scripts.
• Tasks should run in a reasonable time.
• Keep the ecFlow scripts manual page up to date, including details of how to handle failures and who is responsible for the script.
• Keep your task output - at the end of each day, we keep the output of all tasks, tar them up and store them on tape. This allows us to review suites at a later date and is useful in indicating when problems may have started.
• Avoid duplication of scripts. Scripts can easily be made configurable and shareable.