DESIGN OF CLASS HIERARCHIES BASED ON CONCEPT (GALOIS) LATTICES

Building and maintaining the class hierarchy has been recognized as an important but one of the most difficult activities of object-oriented design. Concept (or Galois) lattices and related structures are prese nted as a framework for dealing with the design and maintenance of cla ss hierarchies. Because the design of class hierarchies is inherently an iterative and incremental process, we designed incremental algorith ms that update existing Galois lattices as the result of adding, remov ing, or modifying class specifications. A prototype tool incorporating this and other algorithms has been developed as part of the IGLOO pro ject, which is a large object-oriented software engineering joint rese arch project involving academic and industrial partners. The tool can generate either the concept lattice or several variant structures incr ementally by incorporating new classes one by one. The resulting hiera rchies can be interactively explored and refined using a graphical bro wser. In addition, several metrics are computed to help evaluating the quality of the hierarchies. Experiments are presented to better asses s the applicability of the approach. (C) 1998 John Wiley & Sons, Inc.