Kuo-n Hsu

Modeling imprecise requirements with fuzzy objects

Abstract One of the foci of the recent development in object-oriented modeling (OOM) has been the extension of OOM to fuzzy logic to capture and analyze informal requirements that are imprecise in nature. In this paper, a new approach to object-oriented modeling based on fuzzy logic is proposed to formulate imprecise requirements along four dimensions: (1) to extend a class by grouping objects with similar properties into a fuzzy class, (2) to encapsulate fuzzy rules in a fuzzy class to describe the relationship between attributes, (3) to evaluate the membership function of a fuzzy class by considering both static and dynamic properties, and (4) to model uncertain fuzzy associations between classes. The proposed approach is illustrated using the problem domain of a meeting scheduler system.

Modeling software architectures with goals in virtual university environment

Abstract Recently, the coupling of goal-based and user-centered approaches has resulted in a tremendous impact on the research of software engineering. However, there is no systematic way in the extant approaches to handling the effects of requirements on the structuring of software architectures. As an attempt towards the investigation of the interactions among goals, scenarios, and software architectures, we proposed, in this paper, a goal-driven architecture trade-off analysis method to analyze and construct software architectures in an incremental manner. We also identified criteria for architecture evaluation and verification and explored the possible types of realization of software architectures for goals. The proposed approach is illustrated using the problem domain of virtual university environment.

Discovering Early Aspects through Goals Interactions

Aspect-oriented approaches have resulted in a great impact on the processing of system properties during the development of software systems. However, a systematic way for eliciting early aspects from requirements is still underdeveloped to better integrate early aspects with the analysis results. As an attempt towards the investigation of the interactions among goals, scenarios, and early aspects, we proposed, in this work, a goal-driven approach to the discovery of early aspects by means of a bidding process that organizes goals into goal clusters for discovering aspectual candidates by exploring the interactions among goals and use cases. By introducing early aspects, the goal-driven approach can be further enhanced to deal with the crosscutting properties in the analysis stage of software development. The proposed approach is illustrated using the problem domains of meeting scheduler system.

Task-based conceptual graphs as a basis for automating software development

It is widely recognized that requirements engineering is a knowledge‐intensive process and cannot be dealt with using only a few general principles. Since knowledge plays a crucial role in software development, software engineers have to describe and organize various aspects of knowledge before the program can be written. A recent work by Robillard reveals that software development can be further improved by recognizing the relevant knowledge structures. In this paper, we propose the use of a task‐based conceptual graphs (TBCB) framework as a basis for automating software development. By structuring and operationalizing conceptual graphs, TBCG specifications can be transformed into executable programs automatically. To construct a conceptual model, task‐based specification methodology is used as the mechanism to structure the knowledge captured in conceptual models, whereas conceptual graphs are adopted as the formalism to express task‐based specifications and to provide a reasoning capability for the purpose of automation. Once task‐based graphs have been constructed and verified, a blackboard system will automatically transform TBCG specifications into a software system composed of database schemas, knowledge base, and user interfaces. A meeting scheduling system is used as an illustrative example to demonstrate our approach. © 2000 John Wiley & Sons, Inc.

GEA: A Goal-Driven Approach toDiscovering Early Aspects

Aspect-oriented software development has become an important development and maintenance approach to software engineering across requirements, design and implementation phases. However, discovering early aspects from requirements for a better integration of crosscutting concerns into a target system is still not well addressed in the existing works. In this paper, we propose a Goal-driven Early Aspect approach (called GEA) to discovering early aspects by means of a clustering algorithm in which relationships among goals and use cases are utilized to explore similarity degrees of clustering goals, and total interaction degrees are devised to check the validity of the formation of each cluster. Introducing early aspects not only enhances the goal-driven requirements modeling to manage crosscutting concerns, but also provides modularity insights into the analysis and design of software development. Moreover, relationships among goals represented numerically are more informative to discover early aspects and more easily to be processed computationally than qualitative terms. The proposed approach is illustrated by using two problem domains: a meeting scheduler system and a course enrollment system. An experiment is also conducted to evaluate the benefits of the proposed approach with Mann-Whitney U-test to show that the difference between with GEA and without GEA is statistically significant.

Applying Software Effort Estimation Model Based on Work Breakdown Structure

Software effort estimation is an important activity for effective project management. To support the prediction of efforts in the early stage of a software project development, we propose an effort estimation model along with a software effort estimation process to estimate project efforts from high level WBS. The proposed estimation model is composed of four original task assignment factors - team size, concurrency, intensity, and fragmentation and one newly proposed factor, named WBS effort. To demonstrate the feasibility of proposed model, a case study is presented. The result of the case study shows that comparing the proposed model with those that using original task assignment effort estimation model, the accuracy of the prediction is improved by applying the five factors. For the data examined, the proposed model also shows to have better results in goodness of fit and quality of estimation than original one.

Modeling requirements with goals in virtual university environment

In recent years, goal based requirements analysis methods have attracted increasing attention in the area of requirements engineering. However, there is no systematic way in the existing approaches to handle the impacts of requirements on the structuring of software architecture. As an attempt towards the investigation of the interactions among goals, scenarios, and software architectures, we propose a goal based approach to building software architecture based on the interactions in an incremental fashion. The proposed approach is illustrated using the problem domain of a virtual university environment.

Structuring requirements specifications through goals interactions

One of the foci of the recent developments in requirements engineering has been the study of conflicting requirements. However, there is no systematic way in the existing approaches to handling the interactions among requirements and their impact on the structuring of requirement specifications. In this paper, a new approach is proposed to formulate the requirement specifications based on goal interactions (i.e., cooperative, conflicting, counterbalanced and irrelevant).