When modeling in viflow, the following message may appear:
The object is already used on a higher level and cannot be added.

When does this message appear?

You are modeling a process graphic and, among other things, are using processes already saved in the process model. New processes can be easily inserted into the graphic, and some existing processes in the process model can also be inserted – only for some of these processes will the above message appear.

Why does this message appear?

If this action were not intercepted, a recursion or infinite loop would occur. The process model could then no longer be loaded because the process structure would branch infinitely.

Due to the hierarchical structure (see the Process Structure window), a process cannot be both the "predecessor" and "successor" of another process. This message often occurs in process models that branch into many levels and have thus become confusing. The frequent reuse of individual processes can be one reason for this:

Processes that you only want to reference, along the lines of "see also...", are dragged from the process structure onto the graphic and thus quickly become subprocesses of the process currently being modeled. If this happens frequently and with many (main) processes that branch out to multiple levels, this effect is naturally amplified.

What can I do to stop this message from appearing?

1. Avoid unnecessary nesting

Frequent reuse of processes creates many levels – often too many to fully understand and oversee the model.

Don't get me wrong: Of course, you can and should reuse individual viflow objects—that's the whole point, and it distinguishes viflow from tools without a database. Try to limit the reuse of main processes to the necessary minimum and occasionally review your work according to the following criteria:

• Is the hierarchy of processes correct in the process model? Is it logical that (for example) the entire order processing, including all subprocesses, is contained in a quotation process?
• Think about your colleagues. If you, as a modeler, have trouble with orientation, viewers have little chance of understanding the model and finding their way around.
• Occasionally, treat yourself to a complete view of the entire model. We recommend expanding the entire process tree by clicking on the individual [+] symbols. Starting at the very top of the process structure, the tree grows in length and width with each click.
  

2. Working with connectors

If you want to reference another process, use a connector that creates a link between the processes. Viewers of the WebModel can use the connectors to jump directly to the linked process. This keeps your process model clear, functional, and maintains a clear, logical structure.