Beshoy Morkos

Predicting requirement change propagation, using higher order design structure matrices: an industry case study

This research examines higher order design structure matrices as requirements change modelling tools to predict requirement change propagation through two large-scale industry design projects. Due to the iterative nature of design, requirements will evolve and change. Changes in requirements can propagate to other requirements on different subsystems leading to possible increases in the project cost and lead-time. Predicting these requirement changes enables the designers to foresee unanticipated changes and maximises the probability for the projects success. These studies reveal that second-order relationships are influential in predicting requirement change propagation. Unforeseen propagation occurring in first-order form was rare, rather it was occurring in second order. Modelling requirements change exposes these secondary relationships early in the engineering change (EC) definition process, thereby enhancing the decision-making process and augmenting cost estimation. A modelling tool, such as that proposed in this paper, can provide the designer insight into the requirements which may be affected before approving an EC.

A Hierarchical Modeling Scheme With Non Functional Requirements

This paper presents a sequence of multi domain matrix based modeling scheme, that includes non functional design requirements, to capture conceptual design information. The current matrix based modeling schemes are congruent to the steps followed in typical design processes but are limited to functional requirements. An industrial case study is analyzed to understand how and where the non functional requirements contribute to the design. It is observed from the case study that the non functional requirements drive the design decision process and constrains the way the product functionality is realized. Based on the observations made in the case study, a sequence of multiple domains is proposed: functional requirements to functions, functions to working principle, working principle to non functional requirements, non functional requirements to components, components to design parameters, design parameters to test measures and test measures to tests. This sequence is realized in a matrix based hierarchical modeling scheme, to capture the conceptual design information.Copyright

Requirement Modeling Systems for Mechanical Design: A Systematic Method for Evaluating Requirement Management Tools and Languages

Requirements engineering has received increased attention in mechanical design as systems have become increasingly complex. Requirements engineering involves several key activities including eliciting, modeling, and analyzing requirements. Problems with requirements engineering include addressing requirements generated from multiple design perspectives, communicating requirements across the design team, and understanding how requirements affect other product design information. Several requirement management tools have been developed to address these issues. However, evaluating the capabilities of current and next generation tools has not been systematically addressed. In this paper, a systematic approach and example problem are developed to evaluate the capability of modern requirements management tools. First, eight capabilities are identified from existing literature and industry design problems. Next, a baseline example problem is developed and implemented in two requirement management tools, namely IBM DOORS and NoMagic MagicDraw+SysML. The evaluation results show that each software tool addresses seven of the eight capabilities to a varying degree, with the exception of input validation of an individual requirement. Further, SysML offers a robust and descriptive set of relationships for modeling complex engineering systems that are useful for requirements analysis. Finally, the research is not intended to be a complete survey of all requirements management tools, but rather to provide a repeatable and systematic method for evaluating and developing requirements management tools.Copyright

Requirement Change Propagation Prediction Approach: Results From an Industry Case Study

This paper presents an industry case study investigating change propagation due to requirement changes. This paper makes use of a change propagation prediction tool, ΔDSM, to identify if the propagated changes could have been identified and predicted. The study used an automation firm’s client project as the study subject. The project entailed 160 requirements, changing over the span of 15 month. Engineering change notifications were developed for each change and documented under the firm’s data management system. This study makes use of the change notifications to identify if any of the change were as a result of a previous change. The findings of this paper indicated the changes that occurred could have been predicted as the ΔDSM was able to predict affected requirements. This was identified by finding subsequent requirements in the engineering change notification documentation that the ΔDSM indicated might change.Copyright

Conceptual Development of Automotive Forward Lighting System Using White Light Emitting Diodes

This paper focuses on redesigning the headlamp subsystem functional architecture. The design involves meeting three major functional requirements: 1. Achieving the lumen requirements according to Economic Commission for Europe (ECE) 324 regulations

Elicitation and Development of Requirements Through Integrated Methods

This paper presents a case study of requirements elicitation for the development of computational support tools at an automotive OEM. The challenges presented in the requirements development necessitated the fusion of three distinct requirements elicitation approaches: traditional design, participatory design, and use case modeling through UML. The findings suggest that a single mode of operation is not sufficient and that to capture the requirements, it is preferred to borrow tools and methods from multiple domains. This case study serves as a broader motivation for a systematic development of engineering requirements modeling and analysis methods.Copyright

INVESTIGATION OF DESIGN TOOLS AS COMPLEXITY MANAGEMENT TECHNIQUES

Design tools which appear to manage complexity through their inherent behavior do not appear to have been developed specifically for complexity management. This research explores how complexity is managed within the design process through: the generation of complexity within the design process (sources), the techniques which were used to manage complexity (approaches), and the examination of design tools with respect to complexity. Mappings are developed between the sources, the approaches, and the tools with respect to phases of design. The mappings are propagated through these distinct, yet adjacent domains in order to study how the tools might be able to be used to manage complexity sources found in different stages of the design process. As expected, the highest value for each design tool is found in the stage of design in which the tool is traditionally been used. However, there are secondary ratings which suggest that design tools can be used in other stages of the design process to manage specific aspects of complexity.Copyright

Requirements and Data Content Evaluation of Industry In-House Data Management System

This paper presents an industrial case study performed on an in-house developed data management system for an automation firm. This data management system has been in use and evolving over a span of fifteen years. To ensure the system is robust to withstand the future growth of the corporation, a study is done to identify deficiencies that may prohibit efficient large scale data management. Specifically, this case study focused on the means in which project requirements are managed and explored the issues of perceived utility in the system. Two major findings are presented: completion metrics are not consistent or expressive of the actual needs and there is no linking between the activities and the original client requirements. Thus, the results of the study were used to depict the potential vulnerability of such deficiencies.Copyright

REQUIREMENTS EVOLUTION: RELATING FUNCTIONAL AND NON-FUNCTIONAL REQUIREMENT CHANGE ON STUDENT PROJECT SUCCESS

This paper presents findings from a study of the evolution of requirements in eight parallel student semester long design projects. Weekly requirements documents were collected and analyzed for the number of functional and non-functional requirements defined by each team. Trends were compared with end of project performance success. The findings provide suggestive, not definitive, evidence that (a) a higher number of defined requirements predicted higher project success, (b) early functional requirement definition relates to project success, and (c) it is important to continually evolve the requirements throughout the project. A set of guidelines and recommendations are developed.

Work in progress: How differences in student motivation characterize differences between engineering disciplines

The limited impact of many engineering education reforms may be due in part to treating engineering as a single monolithic discipline. We are using student motivation to characterize differences in engineering majors in order to inform educational practices and differences in student learning. Here we report on differences in student attitudes towards their engineering majors, elucidated through the use of survey data collected from first year students and longitudinal data on their majors 2 years later. We provide a detailed picture of the complexity of the engineering population, which will help direct more in-depth qualitative research to examine possible correlations between student motivation and learning in different engineering majors.