The graphical tool supports Nesting of activities and processes however there are some rules for nesting which are described below

Three activities nested


  1. An Activity can be nested in another Activity or Process
  2. A parent Activity can be nested to other parent or child Activities
  3. A process cannot be nested in an Activity
  4. A process can be nested in another Process
  5. A Process or Activity with connections cannot be nested unless connections are removed first
  6. Tool supports N level of Nesting fulfilling above criteria

How to Nest

To nest one element to another follow these steps:

  1. Select an Activity or Process by left click on it, it’s border will turn to blue this indicates as a source element which is to be nested
  2. Now right click on other Activity or Process and a menu will be shown, click on Nest Under option and the selected item will be nested inside this item


When an Activity or Process is nested it can also be un-nested easily, just right click on the item you want to un-nest and select Un-nest from the menu and the item will be un-nested from its parent. If the item has some connection then remove those connections in certain cases in order to complete the un-nest operation.


We’ve enhanced the DCR semantics and is now supporting two different types of “grouping of events”:

  • Nesting – the “classical” way of grouping events together
  • Single instance sub-process – a new way of “grouping” events which we believe is more intuitively. Once the grouping is Accepting, i.e. no pending events (blue exclamation marks) exists, the sub-process is considered done.

The main difference between nesting and sub-process is that in nesting all events must be executed before you can proceed, while for sub-processes the process must be in accepting mode to continue. This is illustrated with this graph.

1. Nesting vs sub-process

Notice that Continue2 is enabled while Continue1 is not. The reason is that the Subprocess is accepting, i.e. no pending events exists.

Also – notice that no roles can be selected for a sub-process.

You choose between nesting and sub-process in the advanced options dialog as can be seen in the picture 2.

2. Choose between Nesting and Subprocess