One general business requirement for SAP spool/print processing is cheque (check) processing in production environments.
To preserve the sequence of cheque production spools one spool work process is generally configured on an application server. Keeping the sequence of cheques and generally in the case of production environments cheque numbers is vital for business processes.
It is important to note that there is no way to absolutely guarantee sequence except using a server with only one spool work process configured and active for spools where it is critical that the order of sequence is preserved.
In some situations where sequence is vital the option in the spool administrator (transaction SPAD) is used to preserve sequence for a specific output device.
From release 4.0 systems and higher this can be achieved by setting the flag for sequential printing in the Output Device definition in transaction
That being the flag "Process requests sequentially" is checked for this output device in SPAD.
SPAD -> Select the 'Output Device' that you use for printing
-> Click on 'Output Attributes' tab
-> Tick the box for 'Process requests sequentially'
In situations where only one spool work process is configured on an application server or the above selection is set in SPAD for a specific output device and a suspected related performance degradation is experienced or observed and option exists in the spool processing.
It is possible to set so that spool requests are appended to an existing spool request if the attributes are similar. In this way, for example many cheques could be stored in one spool request rather than separate spool request numbers.
For spools to be appended the parameters 'New spool request' and 'Do not Append Print Jobs' must be set to 'No'. In addition there are some additional spool parameters are always compared and must match the corresponding parameters of the document so that the document can be appended to the spool request. these are outlined in the following SAP notes.
85318 - Appending documents to existing spool requests
16410 - Attaching to existing spool requests