The standard workflow for PO release is WS20000075, before trying anything better have a check of blow article first which describes the process and related configuration about the workflow of PO Release Strategy very well.
As not a workflow expert, just list a few FAQs that could help.
Q1: Why workflow is not triggered when PO has been created or changed?
A1: Go to SWETYPV (Type Linkages) or SWE2, and check entry with object category 'BO', object type 'BUS2012'. The event here is not 'CREATED' or 'CHANGED', but 'RELEASESTEPCREATED' instead. This means it'll be created at release step creation not when PO has been created or changed.
Q2: Why has workflow not been triggered after the correct event has been assigned?
A2: Goto SWDD and GOTO->basic data->Start events, check whether the Active icon is green or not. If not green click the button to activate it. Sometimes it'll change back to yellow when you save it as green, it could cause by an incorrect setting inside this workflow. Check inside if any error and may try to remove the flag of 'Enable event queue'.
To investigate the Event Linkage issue, have a look at TCODE:
SWEQADM or check
this.
For workflow transport issues between systems, check
this and
this.
Q3: Who will receive the workflow and where to control agent assignment?
A3: if the 'Agent assignment' icon is been green means at least the agent has been assigned, otherwise there'll be no one getting this workflow at SBWP. For this PO release, the Person responsible for PO release should receive this workflow which is determined by reason code (standard workflow already contain this).
The release code has been transferred at binding:
This release code is fetched by standard rule 20000027 at task '20000166'.
As it'll only trigger once the release step has been created, may require many PO to be created during testing. How to test this workflow by yourself first? Find one Purchase order which meets all criteria like the correct release code assigned, Go to ME23N:
Extra. About deadline monitoring of PO release
Although rule 20000027 has already been assigned to the step but seems no rule assigned at this 'Latest End' tab still no trigger of the workflow at my side. So here set rule 20000027 along with the binding by using define bind automatically. Set small intervals for easy testing purposes.
Check specific workflow by using SWI6:
Check the deadline dates at the container of workflow log like below:
About troubleshooting of workflow: