Combining OCL and Programming Languages for UML Model Processing

Model processing tasks, like model checking, merging, slicing, and synthesis, need efficient and maintainable mechanisms to define models, as well as to query, compare and manipulate information in them. Although the Object Constraint Language (OCL) is primarily meant for expressing constraints for UML models, it can also be used for various model processing purposes. In this paper we discuss the needs for, and possibilities of, using OCL for processing models, and show how we have applied and extended OCL. We also introduce a model processing tool using OCL as an integral part of model manipulation facilities. We especially emphasise the need of combined use of OCL and programming languages in UML model processing.