PABRE: Pattern-Based Requirements Elicitation

This paper presents our PABRE method for facilitating Requirements Elicitation on the basis of Requirement Patterns with the goal of saving time and reducing errors during this activity. The process presented applies for elicitation in Off-The-Shelf selection projects driven by call for tenders processes and uses a Requirement Patterns Catalogue. The process selects patterns from the catalogue that apply to the particular selection project, and convert them into the real requirements that finally configure the project Requirements Book. We show some benefits of the pattern approach for requirements engineers and IT consultants, as well as for customers. Finally we discuss the strengths and weaknesses of the proposal and identify some future work.Peer ReviewedPostprint (published version

How agile COTS selection methods are (and can be)?

Agile methods are proposed nowadays as a way to support software systems procurement. Most of the existing proposals such as eXtreme programming or scrum seem to conceive software procurement as an exercise of software development. However, a great deal of software systems are commercial off-the-shelf (COTS)-based systems, in which the focus changes from bespoke software development to COTS selection and integration. Many proposals for COTS selection have been issued and therefore one may wonder how do they behave from the agile point of view. In this paper, we study the agile principles in the context of COTS selection and we analyze some of the most widespread existing methods. As a result, we identify some practices that would help in making COTS selection processes more agile.Peer ReviewedPostprint (published version

Public eTendering in Portugal: vortalGOV® Case Study

Vortal is the leader in electronic platform operations for public and private market contracting in Portugal and one of four international reference points in electronic public contracting. In 2004, after having achieved a wealth of private market experience acquired through electronic market operations within the construction sector through its brand Econstroi, Vortal launched a new brand, vortalGOV, which is specifically aimed a the public sector and indeed the first ever electronic public tender in Portugal was launched through this Vortal platform. In 2008 a new public contract law came into force directing all entities linked to electronic contracting platform use to formalise pre-contracting. Furthermore, that same law specified that platforms should not charge the economical operators, the suppliers, any fees to access their basic services. In other words, revenues from the Public eTendering platforms should only come from public entities awarding the contracts. In 2009, order to meet these new legal requirements, Vortal launched its free Universal service. In 2010, Vortal decided to contract the services of a specialist company to carry out a satisfaction survey of its Universal clients. The Vortal Board of Directors sought to evaluate possible scenarios for the development of the public sector market drawing on the experience the company had acquired in the private market. The vortalGOV case study aims to stimulate reflection on the innovation surrounding the legal limitations of business operations, based on an analysis of customer value.A Vortal é a empresa líder na operação de plataformas electrónicas de contratação nos mercados público e privado em Portugal e uma das 4 referências internacionais em Contratação Pública Electrónica. Com uma vasta experiência no mercado privado, adquirido através da operação do mercado electrónico para o sector da Construção, o econstroi, a Vortal lançou em 2004 o vortalGOV, para o sector público. O primeiro concurso público electrónico em Portugal foi lançado através da plataforma da Vortal. Em 2008 foi publicada a nova lei dos contratos públicos que obriga todas as entidades vinculadas à utilização de plataformas electrónicas de contratação pública para formalização dos procedimentos de pré-contratação. Esta mesma lei indicada ainda que as plataformas não poderiam cobrar qualquer valor aos operadores económicos, os fornecedores, para acesso aos serviços básicos das mesmas. Isto é, as receitas das plataformas de contratação electrónica seriam apenas provenientes das entidades públicas adjudicantes. Para fazer face a esta contingência, a Vortal lançou logo em 2009 o serviço Universal, gratuito, de acordo com todos os requisitos da lei em vigor. Em 2010 a Vortal decidiu solicitar os serviços de uma empresa especializada para fazer um inquérito à satisfação dos seus clientes Universais. A Administração da Vortal pretende avaliar os cenários possíveis para desenvolver o mercado do sector público a partir da experiência adquirida no mercado privado. O caso de estudo do vortalGOV pretende estimular uma reflexão em torno da inovação em torno de limitações legais à operação do negócio, em função da análise de valor para o cliente

Determining criteria for selecting software components: lessons learned

Software component selection is growing in importance. Its success relies on correctly assessing the candidate components' quality. For a particular project, you can assess quality by identifying and analyzing the criteria that affect it. Component selection is on the suitability and completeness of the criteria used for evaluation. Experiences from determining criteria for several industrial projects provide important lessons. For a particular selection process, you can organize selection criteria into a criteria catalog. A CC is built for a scope, which can be either a domain (workflow systems, mail servers, antivirus tools, and so on) or a category of domains (communication infrastructure, collaboration software, and so on). Structurally, a CC arranges selection criteria in a hierarchical tree-like structure. The higher-level selection criteria serve to classify more concrete selection criteria, usually allowing some overlap. They also serve to leverage the CC.Peer ReviewedPostprint (published version

A Product Line engineering practices model

AbstractThis paper describes work in progress towards the elaboration of a Product Line practices model that combines concepts proposed by various authors. The strengths of existing Product Line frameworks and models are summarized and a new model is proposed in the form of 31 Product Line practice areas, grouped in five categories. An important objective of this Product Line practices model is that it should be easily incorporated into existing development methodologies, while remaining aligned with existing systems engineering standards

Collaborative resolution of requirements mismatches when adopting open source components

[Context and motivation] There is considerable flexibility in requirements specifications (both functional and non-functional), as well as in the features of available OSS components. This allows a collaborative matching and negotiation process between stakeholders such as: customers, software contractors and OSS communities, regarding desired requirements versus available and thus reusable OSS components. [Problem] However, inconclusive research exists on such cooperative processes. Not much empirical data exists supporting the conduction of such research based on observation of industrial OSS adoption projects. This paper investigates how functional and non-functional requirement mismatches are handled in practice. [Results] We found two common approaches to handle functional mismatches. The main resolution approach is to get the components changed by the development team, OSS community or commercial vendor. The other resolution approach is to influence requirements, often by postponing requirements. Overall, non-functional requirements are satisfactorily achieved by using OSS components. Last but not least, we found that the customer involvement could enhance functional mismatch resolution while OSS community involvement could improve non-functional mismatch resolution. [Contribution] Our data suggests that the selecting components should be done iteratively with close collaboration with stakeholders. Improvement in requirement mismatch resolution to requirements could be achieved by careful consideration of mismatches size, requirements flexibility and components quality.Peer ReviewedPostprint (author's final draft

Special Characteristics of Concurrent Engineering Studies dealing with Cubesat missions and their impact on the CE process

The continuously growing commercial and scientific relevance of nanosatellite missions, especially Cubesats, is clearly discernible in the space community. Due to this, it is important to analyse the special characteristics and demands of early phase studies for such missions to consider them in the Concurrent Engineering Facility (CEF), DLR Bremen’s system analysis laboratory. Within such studies, various differences have been observed which make it necessary to adapt the established CE process for study preparation, conduction and post-processing to meet the specific demands of these well-constrained systems, and thereby create the optimal study results together with the design team. On the design level, the major differences can mainly be traced to two closely connected peculiarities of CubeSat design. First, the targeted system is strictly limited in size, mass and form factor by the associated standard. Because of this, and the growing acceptance of Cubesats, a wide set of highly integrated COTS components and complete subsystems exists on the market with detailed datasheets, and even 3D models freely available on the internet. Secondly, this pool of applicable hardware increases the level of detail the study team has to deal with in a CE study, sometimes even down to connector and harness layout. In a nutshell, the process of CE studies has to be adapted for these small systems towards a later-phase like level of detail, while preserving the creative and efficient way of solution finding traditionally associated with the CE process, including known benefits such as time and cost savings, and design quality improvement. Based on conducted CE studies for CubeSat missions, this paper points to some of the most noticeable and important lessons learnt and derives suggestions for possible process adaptations. One of a CE study’s team leader’s main tasks is to make sure the design process is followed in the most efficient way possible. However, different activities or designs require at times a different approach and ad hoc modifications to the traditional CE process. Starting with the findings from the Cubesat experience, it becomes more and more obvious that the proven process and work approach has to be adapted not only depending on the type of activity conducted in the CEF but also on the design team’s background and composition. To exemplify this, the differences for “regular” and CubeSat studies, plus less strictly defined moderated workshops, are analysed in this paper with a special focus on the most promising particular respective communication and guidance styles of the team leaders, as experienced in the CEF

Securing the Participation of Safety-Critical SCADA Systems in the Industrial Internet of Things

In the past, industrial control systems were ‘air gapped’ and isolated from more conventional networks. They used specialist protocols, such as Modbus, that are very different from TCP/IP. Individual devices used proprietary operating systems rather than the more familiar Linux or Windows. However, things are changing. There is a move for greater connectivity – for instance so that higher-level enterprise management systems can exchange information that helps optimise production processes. At the same time, industrial systems have been influenced by concepts from the Internet of Things; where the information derived from sensors and actuators in domestic and industrial components can be addressed through network interfaces. This paper identifies a range of cyber security and safety concerns that arise from these developments. The closing sections introduce potential solutions and identify areas for future research

Modeling high-performance wormhole NoCs for critical real-time embedded systems

Manycore chips are a promising computing platform to cope with the increasing performance needs of critical real-time embedded systems (CRTES). However, manycores adoption by CRTES industry requires understanding task's timing behavior when their requests use manycore's network-on-chip (NoC) to access hardware shared resources. This paper analyzes the contention in wormhole-based NoC (wNoC) designs - widely implemented in the high-performance domain - for which we introduce a new metric: worst-contention delay (WCD) that captures wNoC impact on worst-case execution time (WCET) in a tighter manner than the existing metric, worst-case traversal time (WCTT). Moreover, we provide an analytical model of the WCD that requests can suffer in a wNoC and we validate it against wNoC designs resembling those in the Tilera-Gx36 and the Intel-SCC 48-core processors. Building on top of our WCD analytical model, we analyze the impact on WCD that different design parameters such as the number of virtual channels, and we make a set of recommendations on what wNoC setups to use in the context of CRTES.Peer ReviewedPostprint (author's final draft

On the use of requirement patterns to analyse request for proposal documents

Requirements reuse is still today a difficult goal to achieve. One particular context in which requirements reuse may give more benefits than costs is that of call for tenders projects, due to the similarity of the requirements documents (which take the form of requests for proposal documents, RfPs) from one project to another. In this paper, we present an approach aimed at making systematic the assessment of RfPs that technology providers need to conduct in order to decide whether they present a bid or not in a call for tenders project. The approach extends a metamodel we already defined for the former PABRE method, which has a similar goal but from the perspective of the organization that issues the call for tenders. The method is illustrated with an exploratory case study in the field of the railway systems domain.Peer ReviewedPostprint (author's final draft