Comp150CPA: Clouds and Power-Aware Computing
Classroom Exercise 15 Answers
Spring 2011

group member 1: ____________________________ login: ______________

group member 2: ____________________________ login: ______________

group member 3: ____________________________ login: ______________

group member 4: ____________________________ login: ______________

group member 5: ____________________________ login: ______________

In class we have described BPMN and BPEL. Let's explore BPMN in a bit more detail.

  1. Draw a BPMN diagram for the business process of showing up at random times to try to catch your advisor in his or her office, to get an advising approval.

    I wrote the answer in the Eclipse BPMN editor, and then selected "File/Save as image file..." to create a .jpg. Several finer points:

    1. Every subprocess has a begin and end statement, and a potential error return.
    2. A clock annotation on a subprocess indicates a timeout.
    3. Negotiation about schedule is depicted as a pair of subprocesses, with timeouts.
  2. Draw a BPMN diagram for logging into SIS and checking your grades, including the time limitation that SIS is not available between 6-8 pm every night.

    I did not depict repeated logins or repeated tries to get transcript. The time dependency can be represented by an event or a gate. I chose a gate because it is a bit easier to read.

    Few people know that between 6-8 pm, SIS does sometimes allow you to login, but won't show you anything! This is the behavior that I depicted.

  3. (Advanced) Why is it impossible to translate a BPMN diagram into a BPEL diagram automatically?
    Answer: The BPMN diagram is missing many details, including how long to wait for timing events, bindings of services, etc.