We have a requirement where in we have 3 independant workflows: Change Request(CR),PBI and SBI.
Suppose in CR workflow we come to a state "Approve" we could like to invoke another workflow"PBI workflow". CR being task and PBI being subtask. In PBI workflow we reach a state "In progress" then we invoke another workflow "SBI workflow" this being subtask of PBI. Once all SBIs gets completed then PBI will get closed. This in turn transfers to the CR workflow which in turn reaches a state closed since all the PBIs are completed