Issue - 109 - Compatibility of Abstract and Executable Processes

["Monica J. Martin" <Monica.Martin@Sun.COM>]

Issue 109 talks about more explicitly defining the relationship and 
compatibility of abstract and executable processes. The abstract 
subgroup had briefly discussed if/how to lay the groundwork for 
conformance or compatibility parameters that may be included in this 
specification. See original issue at: 
http://www.oasis-open.org/archives/wsbpel/200403/msg00200.html

Therefore, Ron Ten-Hove and I have provided below an initial 'ready to 
execute' constraint list that could be used to start on a verifiable 
checklist for static analysis.  This could assist us in understanding 
the continuum (referenced in abstract process subgroup) from abstract to 
executable.

    * No <from opaque="yes"> elements in <assign> activities
    * No <opaque> activities [1]
    * No other use of opaque placeholders that we may devise.
    * All variables are initialized before use (where statically
      verifiable).
    * No omission of variable reference attributes in <invoke>,
      <receive>, <reply>, and <onMessage> activities. Variable reference
      attributes defined.
    * Start activity defined (serves as a trigger for the executable
      process).
    * Constrain the initial <receive> to have a correlation set. May
      also affect a singleton instance or multiple instances active in
      parallel. [2] [3]

[1] Given decision on Issue 107
[2] Given decision on Issue 120
[3] Note: If engine-managed correlation is used, this precludes static 
constraints on <process> defined correlation sets (i.e. Inbound messages 
can be "magically" associated with an existing process instance, without 
use of any declared correlation sets).  See issues such as 96.