A sequence diagram sounds like a convenient way to try to represent the duration of an activity, but I think there are some subtler issues involved. Another way to look at your scenario is to say that you are trying to track two changes of state in your Worker instance, from not working to working and from working to not working. Also, is the Worker still in the working state when he sends the Completed message, or is he out of the working state? Philosophically, I would say he is in the non-working state, which means the Completed message should begin its own focus of control.
As has been pointed out, asynchronous activity is difficult to interpret on a sequence diagram. That is because focus of control in a sequence diagram isn't meant to depict chronological duration. For example, when your Worker sends the Completed message, this may start a chain of events in which the Worker isn't involved. Perhaps these take two pages of sequence diagram to complete. In the meantime, the instant after the Worker sends the Completed message, he starts the GoHome activity. Because you are dealing with asynchronous activity, it means he doesn't have to wait until the other two pages worth of activity is completed until he goes home. Therefore, GoHome would again begin its own focus of control, but you can't interpret the distance between Completed and GoHome as time. (If the Worker couldn't GoHome until all of the ancillary Completed activities had occurred, then GoHome should be in the same focus of control as Completed.) ************************************************************************* PRIVILEGED AND CONFIDENTIAL: This communication, including attachments, is for the exclusive use of addressee and may contain proprietary, confidential and/or privileged information. If you are not the intended recipient, any use, copying, disclosure, dissemination or distribution is strictly prohibited. If you are not the intended recipient, please notify the sender immediately by return e-mail, delete this communication and destroy all copies. ************************************************************************* ************************************************************************ * Rose Forum is a public venue for ideas and discussions. * For technical support, visit http://www.rational.com/support * * Post or Reply to: [EMAIL PROTECTED] * Subscription Requests: [EMAIL PROTECTED] * Archive of messages: * http://www.rational.com/support/usergroups/rose/rose_forum.jsp * Other Requests: [EMAIL PROTECTED] * * To unsubscribe from the list, please send email * To: [EMAIL PROTECTED] * Subject: <BLANK> * Body: unsubscribe rose_forum *************************************************************************
