RESS 2012 – Proceedings

Foreword
The Second International Workshop on Requirements Engineering for Systems and Systems and Quality Requirements RESS’12. After the success of the previous workshop (also collocated with the IEEE International Requirements Engineering Conference) this workshop is aimed at bringing practitioners and research experts together for exchanging ideas, knowledge and experience, and at setting a research agenda based on industry needs. Requirements engineering for systems and systems of systems involves not only the requirements for the components, but also the requirements for the infrastructure and interfaces of complex systems of systems. Quality (aka non-functional) requirements are important and integral part of system and system of systems engineering efforts.

Mechatronic Systems

Just-in-Time Traceability for Mechatronics Systems
Adam Czauderna, Jane Cleland-Huang, Murat Cinar, and Brian Berenbach
(DePaul University, USA; Siemens, USA)
Effective traceability can be very costly and difficult to achieve in mechatronics systems due to their overall size and complexity. Such systems are often specified and designed in terms of software, electrical, mechanical, and thermodynamic elements, and associated models are represented and stored in various formats and locations. Traceability is of critical concern in such systems, which must often demonstrably comply to a wide range of regulatory codes. To address this problem we present an enterprise level architectural solution for establishing organization wide traceability across a variety of model types. While our approach is applicable to any enterprise level tracing environment, we focus on the mechatronics problem and illustrate our solution with a prototype tool that delivers semi-automated traceability between the regulatory codes, requirements, and systems models of a mechatronics system.

Analysis of SOS Requirements

System Security Requirements Analysis with Answer Set Programming
Gideon Bibu, Nobukazu Yoshioka, and Julian Padget
(University of Bath, UK; National Institute of Informatics, Japan)
The need for early consideration of security during system design and development cannot be over-emphasized, since this allows security features to be properly integrated into the system rather than added as patches later on. A necessary pre-requisite is the elicitation and analysis of the security requirements prior to system design. Existing methods for the security requirements phase, such as attack trees and misuse case analysis, use manual means for analysis, with which it is difficult to validate and analyse system properties exhaustively. We present a computational solution to this problem using an institutional (also called normative) specification to capture the requirements in the InstAL action language, which in turn is implemented in answer set programming (a kind of logic programming language). The result of solving the answer set program with respect to a set of events is a set of traces that capture the evolution of the model over time (as defined by the occurrence of events). Verification is achieved by querying the traces for specific system properties. Using a simple scenario, we show how any state of the system can be verified with respect to the events that brought about that state. We also demonstrate how the same traces enable: (i) identification of possible times and causes of security breaches and (ii) establishment of possible consequences of security violations.

Visualizing Requirements in Distributed System Development
Deepti Savio, Anitha PC, Arpith Patil, and Oliver Creighton
(Siemens, India; Siemens, Germany)
Distributing the various phases of system development across multiple locations has posed several requirements-related challenges. These challenges directly and indirectly arise from the lack of opportunities for face to face communication and collaboration between project team members, while trying to obtain clarity on requirements. These concerns are more pronounced when the constituent sub-systems in a systems development effort are developed across various locations. Gauging the current ‘status’ of requirements in such a setting is often cumbersome, especially when large volumes of written requirement documents have to be dealt with. Here, we describe a tool that was developed to pictorially visualize a large number of requirements at several levels of granularity, from the perspectives of different stakeholders in a project. The tool was used to capture and store a set of requirements for a sub-system of a healthcare product. We report the results of this experiment, and stress on the importance of supporting ‘decentralized’ requirements engineering from the sub-system point of view.

A Requirements Engineering Content Model for Cyber-physical Systems
Birgit Penzenstadler and Jonas Eckhardt
(TU Munich, Germany)
The development of highly distributed Systems of Systems (SoS) poses a big challenge on the whole development process of such systems. Especially in Requirements Engineering, one has to cope with the resulting variety of stakeholders and their multitude of different and possibly contradictory goals. This is challenging for requirements elicitation, documentation, and management, especially with regard to communication and consistency. One promising means to this challenge is to use an artefact-oriented requirements engineering approach that puts emphasis on artefacts and dependencies rather than dictating processes and methods for creating the artefacts. In this paper, we present a content model that facilitates collaboration between stakeholders from 30 companies in the research project ARAMiS and is used on a SoS; more specifically, on a so-called Cyber-Physical System that spans a variety of application domains. The content model was elaborated iteratively on the basis of models from preliminary work and in discussion with partner representatives. It is now under evaluation by the 30 project partners, so we present a preview of the evaluation.

Product Line Requirements

An Early Look at Defining Variability Requirements for System of Systems Platforms
John Klein, Gary Chastek, Sholom Cohen, Rick Kazman, and John McGregor
(SEI/CMU, USA)
In the commercial domain, platform-based approaches, in which a set of functions or services are bundled to form the basis of many products, have enabled efficient development of systems and their composition into systems of systems. A successful platform must balance sufficient commonality to support economical reuse, while also providing variability and extensibility to enable innovation in system and system of systems (SoS) capabilities. These commonality/variability tradeoffs for SoS platforms are frequently tacit decisions, since there are no accepted techniques for analyzing such decisions at the scale and degree of requirements uncertainty that characterize most SoSs. The objective of our work is to develop a method for analyzing decisions about requirements for common platforms for SoSs. The method begins with the requirements tasks of identifying and selecting appropriate variabilities (variation points, variation ranges, and variation decision binding times) to support immediate SoS needs, and also enable innovation and controlled evolution. We are currently conducting a workshop and interviews with SoS experts to define the essential technical problems in SoS common platform development and identify solution constraints. We will then define a simplified SoS with limited capability requirements to use as a model problem. We will use the model problem to assess the fit of existing scope, commonality, and variability methods from software product lines to the SoS context, and extend existing economic models using real options and probabilistic models to model uncertainty in evolution requirements. While it is too early to draw firm conclusions about the effectiveness of our approach, it is based on proven technologies from the mature field of software product lines and so we have confidence that we can build successful SoS techniques from this foundation. Keywords- component; system of systems; software requirements; platform engineering; software product lines; system of systems architecture

The Effect of Stakeholder Inertia on Product Line Requirements
Krzysztof Wnuk, Richard Berntsson Svensson, and David Callele
(Lund University, Sweden; TR Labs, Canada)
One of the goals of requirements engineering is to capture and document innovation in the form of new product requirements. These product requirements need to express new system functions or new qualities that are most desired by customers while maintaining customer familiarity with existing products. This paper explores the contradiction between the customer desire for revolutionary advancement and their desire to maintain familiarity with existing systems. This customer inertia creates a bias toward incremental (evolutionary) advancement, potentially multiplying the risks associated with revolutionary innovations. We present a review of scenarios illustrating this stakeholder bias and propose a research agenda for further work in the area.

RESS 2012 – Proceedings

Second IEEE International Workshop on Requirements Engineering for Systems, Services, and Systems-of-Systems (RESS)

Mechatronic Systems

Analysis of SOS Requirements

Product Line Requirements