Home > Process Modeling and Simulation Concepts > Transaction Flow > Transaction Processing Order Inside a Shape

Transaction Processing Order Inside a Shape

Transactions follow a sequential set of steps once they enter a shape (e.g. an activity). Certain operations are performed in a shape at a particular step or set of steps. The following steps of transaction sequence flow refer to the page of the Properties dialog box where the operation is specified:

1. Set Enter attributes (Attributes page)

2. Process (or wait on) Inputs (Inputs page)

3. Set Post-Input attributes (Attributes page)

4. Acquire Resources (Resources page)

5. Set Pre-Task attributes (Attributes page)

6. Perform Task Step, such as duration (Task page, Step tab)

7. Set Post-Task attributes (Attributes page)

   If Repeat is specified, do steps 6 and 7 while the Repeat condition is true.

8. Release Resources (Resources page)

9. Perform Task On Completion (Task page, On Completion tab)

   Send Message is one of the operations performed in this step. However, if the message is marked to receive data, it blocks the transaction from proceeding further and the transaction waits here until the return message is received. Marking a message to receive data is not standard BPMN behavior.

    

10. Perform Normal Outputs operations (Outputs page, Normal tab)

    If any exceptions are specified on the Exceptions tab of the Outputs page, they may occur at any time during transaction processing at this shape unless they are disabled at certain points, such as after Resources are acquired. See the discussion on exceptions below.

     

11. Update Last Simulation statistics

12. Set Exit attributes (Attributes page)

If the shape properties specify to create transactions at input (Generate Here) or introduce transactions to this shape (Using a Start Point), the shape receives transactions prior to step 1.

Exceptions may occur any time from the time Enter attributes are set to the time all output operations are complete. From the point at which the exception occurs, transactions branch out of the 12-step sequence and continue on with the following sequential steps: a) Release Resources; b) Set Exception Attributes; c) Update Last Simulation Statistics; and d) Set Exit Attributes

Timer exceptions can use the Disable settings After Input, After Resource, or Never. This causes the exception to be active only from step 2 through 3 (disabled After Input), step 2 through 5 (disabled After Resource), or steps 2 through 10 (never disabled).

Related Topics