Approval Workflow Features 
You can use the following features to adapt flexibly the approval workflow process flow at runtime.
Back-and-Forth Processing
In a process level of the type approval with completion, this property enables the creator of a purchasing document and the currently responsible agent to communicate with each other, for example, in the case of open questions or changes to the document. By using the Inquire pushbutton provided by the Universal Worklist (UWL), the approver can send the work item back to the creator including, if necessary, a comment or question. The creator can then change the document and send it again.
In a process level of the type approval, back-and-forth processing is possible in the case of rejected items:
In the case of a partial rejection, the requester receives a work item informing him or her about the rejection. The requester can then change the document.
In the case of a complete rejection, the requester receives a work item if the system has been configured accordingly in Customizing for SAP Supplier Relationship Management (SAP SRM) under
SRM Server 
Cross-Application Basic
Settings Business Workflow Process-Controlled Workflow Business Process Configuration Define Process Levels 
. The requester can then change the document.The requester can also select Work Item to Requester at Process End in the approval process overview while creating a shopping cart. The system then sends a work item even if this has not been configured in Customizing.
Inserting Ad Hoc Agents
Any person participating in a workflow process can insert ad hoc agents in addition to the responsible agents that the system determines based on the process schema. The system creates a work item for the ad hoc agent on any process level after the current one. The decision set and the decision type for the ad hoc agent are identical to the ones in the current process level.
Inserting Reviewers
You can add reviewers to the approval process. Reviewers can follow the entire approval process for a procurement document, independent of which decision type applies. In particular, they can do the following:
Display the document
Display existing attachments or create new ones
Add notes
Insert further reviewers
Reviewers cannot approve or reject the document and they cannot add further approvers. The system records whether the reviewer has accessed the work item or taken any action.
The following options are provided to add reviewers:
User adds ad hoc reviewer
Document creators and approvers who are assigned a work item can add ad hoc reviewers to the approval process.
The Business Add-In (BAdI) Adjust Search Help for Reviewer (/SAPSRM/BD_WF_REVIEWER_F4) allows you to specify who is authorized to add ad hoc reviewers and who can be added as an ad hoc reviewer.
System adds reviewers based on rules
Apart from adding ad hoc reviewers, it is also possible to configure the system such that reviewers are inserted automatically into the approval process, according to rules. The system determines reviewers in the same way that it determines approvers, for instance, by specific document fields, such as product category or accounting type, by business object attributes, or by specific roles or users.
The BAdI Define Reviewers (/SAPSRM/BD_WF_REVIEWER_RULE) is supplied to assign documents to groups of agents for review.
Note
Document changes during an approval process can have an impact on the reviewer assignment.
Forwarding Work Items
Forwarding work items is a feature provided by the UWL. Any recipient of a work item can use the Forward pushbutton in the UWL to forward the work item to another user. You can search for a certain user in a list and forward the work item to this user. The selected user can then process the work item.
Caution
The list of users is not restricted to the possible agents of a work item.
Note
Forwarding work items can also be done using the Business Workplace (transaction code SBWP).
Forwarding for Administrators
Administrators may want to forward work items that they have not received themselves in their UWL. For instance, forwarding work items might be necessary if the responsible agent assigned to the work item is not available.
You can forward work items as an administrator by using transaction SWIA, a feature of the SAP Business Workflow. Enter selection criteria to search for a specific work item. Select the work item and choose the Administrator Forward pushbutton. Administrators can also process the work item or send it back to the requester.
Assigning Substitutes
Assigning substitutes, for example, for periods of absence, is a feature provided by the UWL. Depending on the substitution rules you set, substitutes can receive your work items directly in their UWL, or they can actively take over your work items. For more information, see SAP Help Portal
at http://help.sap.com under SAP Library Getting Started – Using SAP Software Working with Tools and Features Using Universal Worklist Features
in the UWL Substitution .
Process Restart
Restarting an approval process is necessary if the requester or the responsible agent changes the document.
Using the BAdI Manage Process Restarts (/SAPSRM/BD_WF_PROCESS_RESTART), the system can override the standard system behavior for process restarts. The process is then restarted at the same active level.
Note
In the case of a complete process restart, ad hoc agents that have previously been added are not taken into account. They must be added again.
If you override the standard process, you cannot add an ad hoc approver at the process level that precedes the active process level.
If a process restart takes place, all existing work items are called back and deleted. The system does not start a new process instance. Process levels that have already been processed are not removed from the process history.