Abstract:
Pattern-based design, the use of design pattern during the design process, has become
widely used in the object-oriented community because of the reuse benefits that take less
cost and effort, but result in high quality in software development and maintenance.
However, design pattern defects can be injected in early design without mandatory
control of the evolution of a pattern-based design and assessment of pattern-based
designs after changes. It is crucial to maintain correct designs during early design
maintenance because defects in early design may cause serious damage to software
systems in later software development and maintenance.
Hence, there is a need of a systematic design method for preventing design pattern
defects being injected during pattern-based design maintenance so that the change results
of pattern-based designs conform to the corresponding design patterns. Conventional
Unified Modeling Language (UML) 2.0 design methods do not provide systematic ways
of assessing pattern-based design conformance.
Pattern Instance Changes with UML Profiles (PICUP) design method is developed as an
improved design method for perfective and corrective UML pattern-based design
maintenance and assessment. Design pattern in UML Profiles (DPUP) is developed for
formal specification of a design pattern. DPUPs are used for instantiation, maintenance,
and assessment of UML pattern-based designs. DPUPs, as the main part of PICUP design
method, provide metamodel-level UML design constraints using UML stereotype
notations and metamodel-level Object Constraint Language (OCL) design constraints.
In this research, assessments of pattern-based designs in UML class diagram with the
corresponding DPUPs enforce maintainers to make correct changes of the designs.
Pattern-related information is annotated in pattern-based design using stereotype
notations. Furthermore, the conformance checking of a given UML pattern-based design
can be automated by using the assessment tool.
An explanatory two-case study is used to evaluate the effectiveness of PICUP design
method with DPUPs, and applied to (1) the Lexi document editor and (2) the ARENA
game information system. Questionnaire answers and design pattern defect counts from
the two-case study conducted by subject matter experts support the hypothesis that the
PICUP method is an improved design method ensuring structural conformance of UML
pattern-based designs to the corresponding design patterns during perfective and
corrective design maintenance for information systems.
