One of the approaches to improve program understanding is to extract what kinds of design pattern are used in existing object-oriented software. This paper proposes a technique for efficiently and accurately detecting occurrences of design patterns included in source codes. We use both static and dynamic analyses to achieve the detection with high accuracy. Moreover, to reduce computation and maintenance costs, detection conditions are hierarchically specified based on Pree's meta patterns as common structures of design patterns. The usage of Prolog to represent the detection conditions enables us to easily add and modify them. Finally, we have implemented an automated tool as an Eclipse plug-in and conducted experiments with Java programs. The experimental results show the effectiveness of our approach.

Design patterns can be regarded as an approach to encapsulate and reuse good design practices. However, most design patterns are specified using informal text and examples. To obtain all of the benefits of patterns, formal specification and tool support are indispensable. This paper proposes a Design Pattern Specification Language (DPSL) that is both manageable and effective. The DPSL provides software developers with the capability to treat design patterns as concrete design units without lowering abstraction. To demonstrate the usability of our DPSL and its application in design modeling, we have developed a prototype tool that supports the DPSL in UML diagrams. This prototype allows us to demonstrate the tool's support possibilities and the usability of patterns for software development applications.

A knowledge gap between network operators and system developers in Network Management System (NMS) construction has widened. This has been caused by an expansion of supported business processes and increasingly sophisticated network management functions. This gap makes system development costly and time consuming. Function development, led by operators, is a promising solution to the problems caused by the gap. This type of development should not require an operator to know how to develop NMS. Standard objects may be used to meet this requirement and save time and the cost of NMS construction. However, they are not sufficient to design functions supporting some tasks that are for providing custom services. In this paper, we propose a partial extension package, composed of several object classes. This package is attached to the standard objects to design a custom function. Information processing in a new function can be added, and easily modified, using this package. This package specifies states that invoke the information processing. It also includes objects that add new data without changing standard objects. It makes use of several design patterns in order to weaken coupling to the standard objects. We have applied this package to two programs. One plans maintenance tasks schedules, the other sets threshold values for quality of service. We made use of software metrics to measure their performance in terms of flexibility. The results show that the proposed package continues to make it possible to reuse the standard objects, and makes it easy to modify the behavior of a new function.

Design patterns which Erich Gamma advocates is expected as an effective approach for the reuse of designs. So, design patterns are predicted to be used frequently in object-oriented software development. In such circumstance, tools to support applying design patterns to the design diagrams of the system under development are thought to be useful. This research develops Object-Oriented Pattern Applying Support tool OOPAS. It consists of a library of Gamma design patterns with very familiar examples and adrem explanation, and of a function to generate the correctly modified design diagrams of the application system when a design pattern was applied to evolve that system. Actually, these functions are installed in the structured object modeling environment SOME, which is an object-oriented design diagram editor made previously in our laboratory. This design diagram evolving function is formalized as a Join operation of the recursive graph. As a result of the evaluation experiment, the join operation can be applied to the almost of the twenty three Gamma design patterns excluding the six patterns such as Iterator and Command, which are stated at too abstract level to be represented by the design diagrams.