Identifying Conflicting Requirements in Systems of Systems

A System of Systems (SoS) is an arrangement of useful and independent sub-systems, which are integrated into a larger system. Examples are found in transport systems, nutritional systems, smart homes and smart cities. The composition of component sub-systems into an SoS enables support for complex functionalities that cannot be provided by individual sub-systems on their own. However, to realize the benefits of these functionalities it is necessary to address several software engineering challenges including, but not limited to, the specification, design, construction, deployment, and management of an SoS. The various component sub-systems in an SoS environment are often concerned with distinct domains; are developed by different stake-holders under different circumstances and time; provide distinct functionalities; and are used by different stakeholders, which allow for the existence of conflicting requirements. In this paper, we present a framework to support management of emerging conflicting requirements in an SoS. In particular, we describe an approach to support identification of conflicts between resource-based requirements (i.e. requirements concerned with the consumption of different resources). In order to illustrate and evaluate the work, we use an example of a pilot study of an IoT SoS ecosystem designed to support food security at different levels of granularity, namely individuals, groups, cities, and nations

Competitive Information Systems in Support of Pricing

Considerable attention has recently been paid to the opportunities presented by information systems technology for implementing, or even driving, corporate strategy. But organizations attempting to identify systems that provide competitive advantage are finding the search to be frustrating and often unrewarding. This paper combines two familiar information systems concepts, the Anthony model and information attributes, to produce a framework for identifying one class of competitive information systems, systems in support of product pricing. For the vast majority of companies operating in imperfect markets, pricing is an information intensive process, in which ambiguous cost projections are balanced with elusive estimates of demand in an attempt to satisfy conflicting stakeholders. As such, pricing presents a rich opportunity to creatively apply information systems technology for competitive advantage. To assist in identifying applications we present a framework to structure the search and a series of working examples that can motivate synergistic discovery. The framework, shown below, categorizes pricing information systems according to decision type and information attributes. The Y-axis contains the three levels of management decision making proposed by Anthony [1965]; four areas of pricing decision-choosing a pricing strategy, setting the basic price level, determinign the price structure, and the price administration- are mapped into the Anthony model. The X-axis includes categories of information attributes taht information systems are likely to impact. We illustrate the matrix by mapping examples into the cells. We are hopeful that readers familiar with a particular firms\u27s attributes and competitive environment will find that the examples help stimulate the discovery of new pricing applications. The paper concludes with some thoughts on using the framework. An appendix to the paper presents a pricing primer for those unfamiliar with the pricing process and its information requirements

Optimal design of metal/elastomer hybrid lattices for combined stiffness and damping

A number of advanced engineering systems require structures that are stiff and strong, while being capable of efficiently damping vibrations. These conflicting requirements are typically addressed by connecting two components, one providing stiffness and strength and the other offering an energy loss mechanism. Combining these opposing functions in a single architected material (possibly hybrid) could result in significant weight savings. This research explores the design space of solid elastomeric truss lattice materials coated with metallic films, and aims at identifying the lattice architecture that optimizes the combination of stiffness, strength and vibration damping.Outgoin

Virtual Engineering in Skills Acquisition and Development in the Career of the Rotorcraft Engineer

As the complexity of engineering systems grows, engineers increasingly need to be able to use a range of tools in order to reduce the costs, and associated risks, as they work in the various phases of the engineering life-cycle. In order to help engineers operate successfully within this product lifecycle, there have been significant developments in modelling simulation tools. Integrating these tools in a Virtual Engineering (VE) environment allows engineers to examine the potentially conflicting requirements of the different phases of the life-cycle, to develop a co-ordinated approach to requirements capture and product design through to identifying potential costly problems that could occur later in the development and operations phases. Technical skills development to use these tools is key to this process. This paper presents the experiences, learning outcomes and lessons learned in the development and implementation of bespoke rotorcraft engineering training programmes. The programmes were designed using a Problem Based Learning (PBL) framework where knowledge and skills are gained through solving problems. Four cases studies are presented in the paper, demonstrating how this PBL/VE approach can be used in the training programmes. Consideration of the future use of VE tools is provided together with future challenges for their successful application

Computationalcost Reduction of Robust Controllers Foractive Magnetic Bearing Systems

This work developed strategies for reducing the computational complexity of implementing robust controllers for active magnetic bearing (AMB) systems and investigated the use of a novel add-on controller for gyroscopic effect compensation to improve achievable performance with robust controllers. AMB systems are multi-input multi-output (MIMO) systems with many interacting mechanisms that needs to fulfill conflicting performance criteria. That is why robust control techniques are a perfect application for AMB systems as they provide systematic methods to address both robustness and performance objectives. However, robust control techniques generally result in high order controllers that require high-end control hardware for implementation. Such controllers are not desirable by industrial AMB vendors since their hardware is based on embedded systems with limited bandwidths. That is why the computational cost is a major obstacle towards industry adaptation of robust controllers. Two novel strategies are developed to reduce the computational complexity of singlerate robust controllers while preserving robust performance. The first strategy identifies a dual-rate configuration of the controller for implementation. The selection of the dualrate configuration uses the worst-case plant analysis and a novel approach that identifies the largest tolerable perturbations to the controller. The second strategy aims to redesign iv the controller by identifying and removing negligible channels in the context of robust performance via the largest tolerable perturbations to the controller. The developed methods are demonstrated both in simulation and experiment using three different AMB systems, where significant computational savings are achieved without degrading the performance. To improve the achievable performance with robust controllers, a novel add-on controller is developed to compensate the gyroscopic effects in flexible rotor-AMB systems via modal feedback control. The compensation allows for relaxing the robustness requirements in the control problem formulation, potentially enabling better performance. The effectiveness of the developed add-on controller is demonstrated experimentally on two AMB systems with different rotor configurations. The effects of the presence of the add-on controller on the performance controller design is investigated for one of the AMB systems. Slight performance improvements are observed at the cost of increased power consumption and increased computational complexity

Systematic innovation and the underlying principles behind TRIZ and TOC

Innovative developments in the design of product and manufacturing systems are often marked by simplicity, at least in retrospect, that has previously been shrouded by restrictive mental models or limited knowledge transfer. These innovative developments are often associated with the breaking of long established trade-off compromises, as in the paradigm shift associated with JIT & TQM, or the resolution of design contradictions, as in the case of the dual cyclone vacuum cleaner. The rate of change in technology and the commercial environment suggests the opportunity for innovative developments is accelerating, but what systematic support is there to guide this innovation process. This paper brings together two parallel, but independent theories on inventive problem solving; one in mechanical engineering, namely the Russian Theory of Inventive Problem Solving (TRIZ) and the other originating in manufacturing management as the Theory of Constraints (TOC). The term systematic innovation is used to describe the use of common underlying principles within these two approaches. The paper focuses on the significance of trade-off contradictions to innovation in these two fields and explores their relationship with manufacturing strategy development

Integrating security and usability into the requirements and design process

According to Ross Anderson, 'Many systems fail because their designers protect the wrong things or protect the right things in the wrong way'. Surveys also show that security incidents in industry are rising, which highlights the difficulty of designing good security. Some recent approaches have targeted security from the technological perspective, others from the human–computer interaction angle, offering better User Interfaces (UIs) for improved usability of security mechanisms. However, usability issues also extend beyond the user interface and should be considered during system requirements and design. In this paper, we describe Appropriate and Effective Guidance for Information Security (AEGIS), a methodology for the development of secure and usable systems. AEGIS defines a development process and a UML meta-model of the definition and the reasoning over the system's assets. AEGIS has been applied to case studies in the area of Grid computing and we report on one of these

Knowledge creation and visualisation by using trade-off curves to enable set-based concurrent engineering

The increased international competition forces companies to sustain and improve market share through the production of a high quality product in a cost effective manner and in a shorter time. Set‑based concurrent engineering (SBCE), which is a core element of lean product development approach, has got the potential to decrease time‑to‑market as well as enhance product innovation to be produced in good quality and cost effective manner. A knowledge‑based environment is one of the important requ irements for a successful SBCE implementation. One way to provide this environment is the use of trade‑off curves (ToC). ToC is a tool to create and visualise knowledge in the way to understand the relationships between various conflicting design parame ters to each other. This paper presents an overview of different types of ToCs and the role of knowledge‑based ToCs in SBCE by employing an extensive literature review and industrial field study. It then proposes a process of generating and using knowledg e‑based ToCs in order to create and visualise knowledge to enable the following key SBCE activities: (1) Identify the feasible design space, (2) Generate set of conceptual design solutions, (3) Compare design solutions, (4) Narrow down the design sets, (5) Achieve final optimal design solution. Finally a hypothetical example of a car seat structure is presented in order to provide a better understanding of using ToCs. This example shows that ToCs are effective tools to be used as a knowledge sou rce at the early stages of product development process

Towards a Framework for Managing Inconsistencies in Systems of Systems

The growth in the complexity of software systems has led to a proliferation of systems that have been created independently to provide specific functions, such as activity tracking, household energy management or personal nutrition assistance. The runtime composition of these individual systems into Systems of Systems (SoSs) enables support for more sophisticated functionality that cannot be provided by individual constituent systems on their own. However, in order to realize the benefits of these functionalities it is necessary to address a number of challenges associated with SoSs, including, but not limited to, operational and managerial independence, geographic distribution of participating systems, evolutionary development, and emergent conflicting behavior that can occur due interactions between the requirements of the participating systems. In this paper, we present a framework for conflict management in SoSs. The management of conflicting requirements involves four steps, namely (a) overlap detection, (b) conflict identification, (c) conflict diagnosis, and (d) conflict resolution based on the use of a utility function. The framework uses a Monitor-Analyze-Plan- Execute- Knowledge (MAPE-K) architectural pattern. In order to illustrate the work, we use an example SoS ecosystem designed to support food security at different levels of granularity

ERP customization failure: Institutionalized accounting practices, power relations and market forces

Purpose: This paper examines a detailed case study of Enterprise Resource Planning (ERP) customization failure in an Egyptian state-owned company (AML) by drawing on new institutional sociology and its extensions. It explains how ERP customization failure is shaped by the interplay between institutionalised accounting practices, conflicting institutions, power relations and market forces. Methodology/Approach: The research methodology is based on using an intensive case study informed by new institutional sociology, especially the interplay between conflicting institutions, power relations and market forces. Data were collected from multiple sources, including interviews, observations, discussions and documentary analysis. Findings: The findings revealed that the inability of the ERP system to meet the core accounting requirements of the control authorities (the Central Agency for Accountability) was the explicit reason cited for the ERP failure. The externally imposed requirements of the Uniform Accounting System and planning budgets were used to resist both other institutional pressures (from the Holding Company for Engineering Industries) and market and competitive pressures. Research limitations: There are some limitations associated with the use of the case study method, including the inability to generalize from the findings of a single case study, some selectivity in the individuals interviewed, and the subjective interpretation by the researchers of the empirical data. Practical implications: The paper identifies that the interplay between institutional pressures, institutionalised accounting practices, intra-organizational power relations, and market forces contributed to the failure to embed ERP in a major company. Understanding such relationships can help other organisations to become more aware of the factors affecting successful implementation of new ERP systems and provide a better basis for planning the introduction of new technologies. Originality/value of paper: This paper draws on recent research and thinking in sociology, especially the development and application of new institutional sociology. In addition, the paper is concerned with ERP implementation and use and management accounting in a transitional economy, Egypt, and hence contributes to debate about exporting Western accounting practices and other technologies to countries with different cultures and different stages of economic and political development. Classification: Research paper/ case stud