User-centered system design

Asset management is a time consuming and error prone process. Information Technology (IT) personnel typically perform this task manually by visually inspecting assets to identify misplaced assets. If this process is automated and provided to IT personnel it would prove very useful in keeping track of assets in a server rack. A mobile based solution is proposed to automate this process. The asset management application on the tablet captures images of assets and searches an annotated database to identify the asset. We evaluate the matching performance and speed of asset matching using three different image feature descriptors. Methods to reduce feature extraction and matching complexity were developed. Performance and accuracy tradeoffs were studied, domain specific problems were identified, and optimizations for mobile platforms were made. The results show that the proposed methods reduce complexity of asset matching by 67% when compared to the matching process using unmodified image feature descriptors.

In this thesis, a framework for improving model-driven system design productivity with Requirements-Driven Design Automation (RDDA) is presented. The key to the proposed approach is to close the semantic gap between requirements, components and architecture by using compatible semantic models for describing product requirements and component capabilities, including constraints. An ontology-based representation language is designed that spans requirements for the application domain, the software design domain and the component domain. Design automation is supported for architecture development by machine-based mapping of desired product/subsystem features and capabilities to library components and by synthesis and maintenance of Systems Modeling Language (SysML) design structure diagrams. The RDDA framework uses standards-based semantic web technologies and can be integrated with exiting modeling tools. Requirements specification is a major component of the system development cycle. Mistakes and omissions in requirements documents lead to ambiguous or wrong interpretation by engineers, causing errors that trickle down in design and implementation with consequences on the overall development cost. We describe a methodology for requirements specification that aims to alleviate the above issues and that produces models for functional requirements that can be automatically validated for completeness and consistency. The RDDA framework uses an ontology-based language for semantic description of functional product requirements, SysML structure diagrams, component constraints, and Quality of Service. The front-end method for requirements specification is the SysML editor in Rhapsody. A requirements model in Web Ontology Language (OWL) is converted from SysML to Extensible Markup Language Metadata Interchange (XMI) representation.