Requirements Analysis Stage Research Articles

Effort Estimation Approach for Integrated Medical Warehouses

ABSTRACT Medical warehouses are architectural construct of an information system that provides users with current and historical decision support information. But medical warehouse projects suffers from overestimation of resources because of improper estimation approaches which do not suit well on poorly defined architecture of medical warehouses. In this paper, we have first proposed a framework for an integrated medical warehouse that covers the different aspects of health care management. Then we proposed an effort estimation approach based on this framework which is designed to be used at the very early stage of requirement analysis. The data from the three different set of data warehousing projects are studied and the linear regression approach is used to finalize the model. Final effort is estimated using the project size and the different adjustment factors. For analytical estimation of project size and its complexity, extended function point analysis is used and identified object are categorized and their complexity weight age is determined. The proposed approach is validated by studying three different set of projects having different level of complexity. First set contains eight business data warehousing projects completed in different domains. Second set contains medical OLAP projects and third set has clinical data marts. A set of questionnaire is used to estimate the complexity of the project, which has to be filled by the developers after completing the initial requirement analysis. The proposed effort estimation model shows a great improvement as compared to the earlier models used in effort estimation of medical warehousing projects.

Web hypermedia content management system effort estimation model

This study aims at creation of a well defined estimation model which can be used to estimate the effort required for designing and developing the web hypermedia content management systems. The data from the different content management system projects are studied and the linear regression approach is used to finalize the model. This model also provides guidelines to calculate phase wise distribution of effort. The model is designed to help project manager to estimate effort at the very early stage of requirement analysis. A set of questionnaire is used to estimate the complexity of the project, which has to be filled after completing the initial requirement analysis. Final effort is estimated using the project size and the different adjustment factors. For better calculation of these adjustments factors, these are categorized into three categories based on their characteristics such as Production and General system characteristics. This model is proposed to be used differently for the different types of projects. These projects are categorized based on their size and total/build effort ratio. The size of the project is estimated by using the modified object point analysis approach. The estimated effort is further phase wise distributed for better scheduling of the project. Another questionnaire is used to refine the model and it has to be filled by the project managers after completing the project. The proposed model is validated by studying twelve completed projects taken from industry and seventy different projects completed by the students. The proposed model shows a great improvement as compared to the earlier models used in effort estimation of CMS projects.

Natural Language Processing for Conceptual Modeling

A semi-automated approach for the design of databases in enhanced-ERD notation is presented. It focuses on the very early stage of the database development which is the stage of user requirement analysis. It is supposed to be used between the requirements determination stage and analysis. The approach provides the opportunity of using natural language text documents as a source of knowledge for semi-automated generation of a conceptual data model. The system performs information extraction by parsing the syntax of the sentences and semantically analyzing their content.

Experimental comparison of attack trees and misuse cases for security threat identification

A number of methods have been proposed or adapted to include security in the requirements analysis stage, but the industrial take-up has been limited and there are few empirical and comparative evaluations. This paper reports on a pair of controlled experiments that compared two methods for early elicitation of security threats, namely attack trees and misuse cases. The 28 and 35 participants in the two experiments solved two threat identification tasks individually by means of the two techniques, using a Latin-Squares design to control for technique and task order. The dependent variables were effectiveness of the techniques measured as the number of threats found, coverage of the techniques measured in terms of the types of threats found and perceptions of the techniques measured through a post-task questionnaire based on the Technology Acceptance Model. The only difference was that, in the second experiment, the participants were given a pre-drawn use-case diagram to use as a starting point for solving the tasks. In the first experiment, no pre-drawn use-case diagram was provided. The main finding was that attack trees were more effective for finding threats, in particular when there was no pre-drawn use-case diagram. However, the participants had similar opinions of the two techniques, and perception of a technique was not correlated with performance with that technique. The study underlines the need for further comparisons in a broader range of settings involving additional techniques, and it suggests several concrete experiments and other paths for further work.

Systematic transformation of functional analysis model into OO design and implementation

Functional refinement is beneficial to object-oriented (OO) software development, especially for problems with more complex functions. However, the use of functional refinement in OO software development has not received much attention. This paper proposes an enhanced data flow diagram (DFD), called data flow net (DF net), for specifying use-cases through functional decomposition. It proposes a novel approach to complement existing OO software development methods with functional decomposition for realizing use-cases, especially those with more complex functions. In the requirements analysis stage, the proposed approach realizes use-cases through functional refinement and specifies them in DF nets. In the design and implementation stages, it transforms the DF nets systematically and precisely into OO design and implementation. The approach is amenable to automation and a prototype has been developed to support the transformation process. In the development of an OO system, it is seamless to realize some of the use-cases using the proposed approach and the remaining use-cases in the same target system using any existing OO software development methods.

On the Systematic Analysis of Natural Language Requirements with CIRCE

This paper presents Circe, an environment for the analysis of natural language requirements. Circe is first presented in terms of its architecture, based on a transformational paradigm. Details are then given for the various transformation steps, including (i) a novel technique for parsing natural language requirements, and (ii) an expert system based on modular agents, embodying intensional knowledge about software systems in general. The result of all the transformations is a set of models for the requirements document, for the system described by the requirements, and for the requirements writing process. These models can be inspected, measured, and validated against a given set of criteria. Some of the features of the environment are shown by means of an example. Various stages of requirements analysis are covered, from initial sketches to pseudo-code and UML models.

Specialized Product-Line Development Methodology for Developing the Embedded System

We propose the specialized product-line development methodology for developing the embedded system of an MSDFS (Multi Sensor Data Fusion System : called MSDFS). The product-line methodology provides a simultaneous design between software and hardware, high level reusability. However this is insufficient in requirement analysis stage due to be focused on software architecture, detailed design and code. Thus we apply the business model based on IDEF0 technique to traditional methodology. In this paper, we describe the processes of developing Core-Asset, which are requirement analysis, feature modeling, validation. The proposed model gives the efficient result for eliciting features, and ensures the high level reusability of modules performing on embedded system.

Softev: UML-based PSEE environment

Software development processes, as a mean to ensure software quality and productivity, have been widely accepted within the software development community. This research introduces how to assist developers to establish quality management plan and monitor the implementation of software processes quantitatively in a CASE environment. A PSEE (process-centered software engineering environment) named Softev has been brought forward to provide developers the environment to define, execute and monitor their processes. As UML is becoming a standard diagrammatic notation for object-oriented modeling and is spreading rapidly, it has been chosen to express the artifacts developed during the requirement analysis and system design stages. In the early products of software process engineering, most research mainly focus on the representations of complex organizational processes and architectures for process-centered application support environment. However, the metrics of software processes and artifacts was not paid sufficient attention to. This research proposes the attributes to be measured during the development period which enable managers to predict and supervise the software project more precisely.

Identifying integration types for requirement analysis in CIM development

This paper presents the second phase of a computer‐ assisted methodology for requirement and design analysis stages of implementing CIM within small and medium‐size enterprises (SME). The main objective is to cover informational and functional analysis during the CIM system life‐cycle. The methodology aims at using limited expertise, limited staff, and expenditure, making it especially suited for introducing CIM in SMEs. The paper emphasises the integration aspects of the methodology as the key factors in the requirement and design analysis stages of the implementation of CIM. Integration has been taken as the need to have some form of operational collaboration between two or more functions. Four types of integration have been identified for reducing the complexity of data communications and for narrowing the gap between analysis and implementation phases. A computer‐supported information requirement analysis tool has been developed for implementing the methodology. A case study was carried out in the apparel industry to test the methodology.

Design of reliable systems using static and dynamic fault trees

The design process of a reliable system is, by nature, iterative. Traditional approaches to the design of a reliable system follow the requirement determination, preliminary design, analysis, evaluation, and redesign stages until what is regarded as an acceptable design is achieved. The system requirements typically consist of requirements on reliability, cost, weight, power consumption, physical size, etc. Within available resources, there can exist numerous approaches that completely satisfy all the design requirements. However as modern systems are becoming more and more complex, it is difficult to enumerate all the acceptable designs to find the optimal design configuration. A design optimization tool is greatly needed. This paper embeds a genetic algorithm (GA) into a fault tree method to determine the heuristic optimal design configuration of a reliable system. For optimization, a fault tree which can represent the failure causes of potential designs is used. Two new gates (CHO & RED) are introduced in this research. GA are developed and integrated into a fault-tree solver to find the optimal design. Improvement techniques to accelerate GA convergence and to avoid the GA-premature problem are implemented. Multi-objective optimization is discussed and methods for it are developed. Several techniques to accelerate the optimization process are implemented which appreciably reduce the calculation time. Simulation results show that the integration of GA optimization capabilities with fault-tree reliability-analysis provides a robust, powerful system-design tool. The methodology is applied to an example of a cardiac-assist system.

Towards the Development of Effective and Flexible Information Systems

The development of Information Systems which are effective (i.e. satisfy users' needs) and flexible enough to incorporate future changes of user requirements basically depends on the importance given to the requirements analysis stage and to the techniques employed for their development This paper presents a new approach to requirements analysis through an environment called VENUS. The VENUS environment provides a set of tools to support the requirements capture and analysis process so that design and development is more effective and flexible. The construction of user requirements starts by first constructing an Entity-Relationship Model which is then transformed to an Object-oriented Rule-based Model (ORM) where rules are used for the definition of the behaviour of each object class. ORM is then mapped to a graphical Petri-net based model and is validated by employing graphical animation and exploiting formal properties of the underlying Petri-net formalism.

Feasibility study and impact assessment for a knowledge-based information-technology planning system

Failures in attempts to introduce knowledge-based systems, particularly into small businesses, have been attributed to inadequate feasibility exploration and impact assessment at the initial stage of KBS development. The paper shows how these two critical factors have been considered within the exploratory study of an ESPRIT project on an IT planning system. The analysis of the two factors (a) shows how the problem domain influences the method of the feasibility study, and (b) considers prior to development the potential impact of the system on its embedding environment. The proposed method of the feasibility study was dictated by the need to characterize the environment of communication and commitment for action between the small business and its actors, the under-theorized status of the problem domain, and the distributed and context-dependent nature of the knowledge involved. On the basis of the requirements analysis stage of the method, a two-stage procedure was used to evaluate the potential impact of the system. It was concluded that the system will support the organizational and business aims of small firms in terms of improved decision making, an improved decision-making process, and institutionalized decision making. Compared with related work, the method of the feasibility study and the impact-assessment approach have certain advantages.

Designing from ill-defined problems

The majority of current information systems design methodologies imply an oversimplified consideration of organizational context. This suggests that it is unproblematical to requirements analysis. This paper argues that organizational contexts are complex situations and information systems design needs to deal with this at the requirements analysis stage. Also, the role of the designer as organizational change agent needs to be recognized as an addition to the role as information engineer. Methodologies for design can provide guidelines for such a recognition which allow for an improved management of the design process. In this paper, a case study is used to illustrate how soft systems methodology can be used for such. This use is then expanded to consider an addition which is the development of metaphor-based modelling. This was found to be helpful in dealing with an ill-defined and highly political organizational problem. The role of the information systems designer as change agent is reflected upon in the light of this study.