OCL

The Dutch company Klasse Objecten hosts the official OCL centre (www.klasse.nl/ocl). 

The IBM website seems to have surprisingly little information about OCL, though this article by Gary Pollice is brief and clear (www-128.ibm.com/developerworks/rational/library/5390.html).

The tutorial site (www.microgold.com/Stage/WithClassTutorial/WCTutP2S6.htm) for the WithClass CASE Tool includes a section on specifying operations using their propietary approach.  This takes some examples through to C++ code.

Other Operation Specification Techniques

Decision trees are covered in some detail on the American Association for Artificial Intelligence website (www.aaai.org/AITopics/html/trees.html).

There are a number of good examples of decision tables here (www.cems.uwe.ac.uk/%7Ejharney/table.html). This page is provided by John Harney at the University of the West of England.

Operation Specification in General

Some research projects are attempting to come up with a language for specifying processes that is independent of the field in which it takes place. The idea is that the same language could be used for specifying industrial processes, business processes, computer processes, etc.  There is a Process Specification Language site (www.mel.nist.gov/psl/) for a US Government project in this area.