Catálogo de publicaciones - libros

One the most difficult aspects of system conceptualization process is to recognize, understand and manage the trade-offs in a way that maximizes the success of the product. This is particularly important for space projects. In this way, a major part of the system engineer’s role is to provide information that the system manager can use to make the right decisions. This includes identification of alternative architectures and characterization of those elements in a way that helps managers to find out, among the alternatives, a design that provides a better combination of the various technical areas involved in the design. Space mission architecture consists of a broad system concept which is the most fundamental statement of how the mission will be carried out and satisfy the stakeholders. The architecture development process starts with the stakeholder analysis which enables the identification of the decision drivers, then, the requirements are analysed for elaborationg the system concept. Effectiveness parameters such as performance, cost, risk and schedule are the outcomes of the stakeholder analysis which are labelled as decision drivers to be used in a trade off process to improve the managerial mission decisions. Thus, the proposal presented herein provides a means for innovating the mission design process by identifying drivers through stakeholder analysis and use them in a trade off process to obtain the stakeholder satisfaction with effectiveness parameters.

Enterprises need continuous product development activities to remain competitive in the marketplace. Their product development process (PDP) must manage stakeholders’ needs — technical, financial, legal, and environmental aspects, customer requirements, Corporate strategy, etc. -, being a multidisciplinary and strategic issue. An approach to use real option to support the decision-making process at PDP phases in taken. The real option valuation method is often presented as an alternative to the conventional net present value (NPV) approach. It is based on the same principals of financial options: the right to buy or sell financial values (mostly stocks) at a predetermined price, with no obligation to do so. In PDP, a multi-period approach that takes into account the flexibility of, for instance, being able to postpone prototyping and design decisions, waiting for more information about technologies, customer acceptance, funding, etc. In the present article, the state of the art of real options theory is prospected and a model to use the real options in PDP is proposed, so that financial aspects can be properly considered at each project phase of the product development. Conclusion is that such model can provide more robustness to the decisions processes within PDP.

Mistakes or foresight in the earlier phases of product development tend to be amplified over the course of a project. Therefore, having a rigorous approach and supporting tools to identify and filter a development portfolio at the early stages can be highly rewarding. This paper presents an executable specification language, Object-Process Network (OPN), that can be used by system designers to formally represent the development option space, and automate certain model refinement activities at earlier phases of product development. Specifically, an OPN specification model can automatically enumerate a set of alternative development portfolios. OPN also provides an algebraic mechanism to handle the knowledge incompleteness problems at varying phases of planning, so that uncertain properties of different portfolios can be represented and analyzed under algebraic principles.

In addition, it has a recursively defined model transformation operator that can iteratively refine the specification models to simplify or enhance the details of the machine-generated alternatives. A list of successful application cases is presented.

This article intends to shed new light on the system design process. We here suggest the possibility of combining simulation features of an executable meta-language called Object-Process Network (OPN) with the descriptive power of well-known modeling languages such as Object-Process Methodology (OPM), Structured Analysis (SA) or SysML. In the Systems Architecture domain, a great issue one always faces is the great number of options to be considered when designing a system. We must keep in mind that modeling the space of options is actually different from modeling the system of interest. The traditional modeling tools allow us to specify a unique solution, when we should consider the whole set of feasible architectures. On the other hand, OPN is able to help architects to assess all these possible configurations but, as a decision-support tool, it doesn’t offer the descriptive power OPM, SA and SysML do.

In this paper, we present how to integrate several processes using a common reference frame offering various viewpoints. This step is applied to the integration of two standards of quality - ISO 9001: 2000 and CMMI - in order to generate a multivues quality reference frame allowing a certification relative to the two standards. This reference frame takes into account the structure imposed by ISO and the recommendations of CMMI. The implementation of this reference frame is accompanied by the application of the organzational improvement model IDEAL (relative to the implementation of CMMI). This paper is based on the work completed within a software engineering company (SYLIS). Both human and cultural aspects of the company are considered in order to mitigate the problem of acceptability.

Nowadays, the definition of service is demanding machines to turn into human beings. In order to work efficiently, machines need to analyze current situations, perceive user needs and provide users with intelligent, automatic and proactive adaptation that responds to current contexts. System performance will be guaranteed only if we add new features to its behavior, such as: self-adaptation, self-organization, self-configuring, selfhealing, self-optimizing and self-protecting. These challenging automated processes can produce proactive behavior if software engineers change the engineering logic and use the environment context as a solution instead of thinking about it as an obstacle.

The key problem of successful development of software intensive system is adequate conceptual interactions of stakeholders at the early stages of designing. Success of development can be increased with using of AI means including means for modeling of reasoning. In this paper a number of question-answer means for conceptual design is suggested. The base of such means is a question-answer method for conceptual decision of a software project task. All question-answer means are organized as workflows “Interactions with Experience” supported conceptual interactions in corporate network.

The growing complexity of the current space systems results an increasing responsibility for the software embedded in them. This is particularly significant when the systems are employed for space critical missions. Usually the software has rigid real time requirements to fulfil which demands high reliability and a disciplined development process. This paper relates the effort of defining a set of software development processes for the onboard computer flight control software (SOAB), a component of the Brazilian Satellite Launcher (VLS), developed by the Instituto de Aeronautica e Espaco — IAE. To achieve the strict requirements for space missions, the SOAB development team’s degree of maturity and technological proficiency had to harmonize with a well defined set of software development processes integrated into the systems engineering. Furthermore, these processes definition had to consider international space systems engineering standards and standards of quality established by IAE. Best practices in software engineering were considered as well.

This paper presents the tailoring of ECSS software product assurance requirements aiming at the development of scientific satellite payload embedded software by a Brazilian software supplier. The software item, named SWPDC, developed by DBA Engenharia de Sistemas LTDA within Software Factory context, is part of an ongoing research project, named Quality of Space Application Embedded Software - QSEE, developed by National Institute for Space Research — INPE, with FINEP financial support. Among other aspects, QSEE project allowed to evaluate the adherence of a Software Factory processes to INPE’s embedded software development process requirements. Although not familiar with space domain, the high maturity level of such supplier, CMMI-3 formally evaluated, facilitates the Software Factory to comply with the requirements imposed by the custumer. Following the software verification and validation processes recommended by ECSS standards, an Independent Verification and Validation - IVV approach was used by INPE in order to delegate the software acceptance activities to a third party team. ECSS standard tailored form contributions along the execution of the project and the benefits provided to the supplier in terms of process improvements are also presented herein.

The high cost and the compression of the development timescale of a realistic satellite simulator motivated the definition of a set of functional requirements based on standardized space services, which is presented in this paper. In order to improve as much as possible reusability and consequently decreasing cost in development, the use of standards were intensively adopted specially for the satellite independent functions, namely, data handling and communication among ground and on-board systems. Functions related to the on-board data handling computer and its communication with the ground systems were based on the ECSS-E-70-41A standard, which focuses on telemetry and telecommand packet utilization definition. The protocol supporting the ground and on-board system communication, at several layers, were based on the Consultative Committee for Space Data Systems (CCSDS) recommendations. This paper presents a set of generic satellite simulator functional requirements modeled into the UML and SysML use case artifact. The satellite and ground station functions included are as much general as possible, as they were based on practical publications of related works and in space service standards.