Horacio P. Leone

A knowledge-based system for HAZOP studies.: The knowledge representation structure

Abstract The Chemical Process Industry is been forced by the society to improve its standards in safety, environmental effects and product quality. One aproach used to address all these aspects in traditional process industries is the HAZOP study (HAzard and OPerability study). But, the application of this technique to a detailed chemical plant design is a complex and time consuming task. These two aspects and the availability of proved technology to develop computational systems able to manage qualitative knowledge, have motivated the construction of SERO, a knowledge-based system for HAZOP studies. The objective of this project is to generate a system aimed at enhancing the knowledge and creative power of the expert team involved in a HAZOP study. One of the main aspects of SERO, that is presented in this paper, is its knowledge representation structure, which has been developed to encode the different kinds of knowledge used in a HAZOP study. The knowledge representation structure of SERO has been designed and constructed using the object oriented paradigm.

TracED: A tool for capturing and tracing engineering design processes

The design of products or production processes in many engineering disciplines such as chemical, or software engineering, involves many creative and sometimes unstructured activities, with an opportunistic control flow. During these design processes, several models are generated, which have different levels of abstraction of the object being designed. Given the difficulties in dealing with this complexity using an improvised way, there is an urgent need for tools that support the capture and tracing of this process. In this proposal, TracED, a computational environment to support the capture and tracing of engineering design process is presented. It allows defining a particular engineering design domain and supporting the capture of how products under development are transformed along an engineering design process. Particularly, in this work, we consider software architectures design domain. As in any complex process, the support of computational tools is required for enabling its capture.

SIMBAD: A process simulator linked to a DBMS—I: The executive system

Abstract The data-handling capabilities of a commercial data base management system (DBMS) are used to control the information flow in a sequential modular steady-state process simulator. Thus, a new structure for the execution of this type of simulators is presented, in which executable program using a rigid agenda from a command file are called sequentially to reduce the amount of main memory occupied during the execution. All the executable programs, representing the basic simulation modules, recover information from the data base and return the new information generated through a common procedure.

Modeling and simulation of software architecture in discrete event system specification for quality evaluation

Software quality is an important issue in software engineering. The evaluation of software architecture is crucial to achieve quality scenarios, which reduces development and maintenance costs. This work presents a discrete event simulation environment for the software architecture assessment considering both functional and quality aspects. Discrete event system specification (DEVS) formalism and the underlying framework are used to specify the simulation elements. DEVS is based on the system theory and follows the engineering and object-oriented fundamentals to construct complex dynamic systems. The proposed environment is built in a modular and hierarchical way that provides scalability and reusability advantages. Although the proposal is focused on three quality attributes and a few metrics, this approach enables the definition of new elements and metrics related to other quality attributes that can be visible at runtime. A traditional architecture illustrates the proposal, where preliminary computational experiments for this real software system and concrete quality scenarios demonstrate the feasibility of the integrated simulation environment for the software architecture evaluation. In addition, a discussion shows how the results could help architects make design decisions to improve software quality during development.

A model to represent architectural design rationale

When developing a software system, its architecture must be considered so that it can be understood, updated, and improved. In general, considering the architectural artefacts is not enough. The reasons, assumptions and justifications bore in mind by the architects during the architecture design stage must be also known. Nevertheless, not all aspects analysed during the design process can be identified, especially all those alternatives that were evaluated and rejected. In the present contribution, a model to represent the rationale generated by architects during the architectural design is proposed so that it can last over time and it can be retrieved, analysed and reused whenever necessary. The model includes concepts representing architectural artefacts, reasons, assumptions, and decisions and reasoning elements status.

SIMBAD: A process simulator linked to a DBMS—III. The physicochemical properties package

Abstract A system to predict physicochemical and transport properties for a steady state process simulator is presented. The data handling capabilities of the Physicochemical Properties Package are managed by a Data Base Management System. The structure of the physicochemical package is such that it allows access from the simulator as well as from external users without the need to compile and link the particular programs. This is the case of programs for Process Synthesis, Optimization, Equipment Design or simply interactive programs for the prediction of process stream properties. Thus, flexibility of operation is achieved as well as an efficient use of memory. Scope—Easy and prompt access of physicochemical properties has been one of the main problems associated with the design of chemical processes and the evaluation of process equipment performance. Large amounts of research have been done into the experimental determination of the physicochemical properties, as well as in the development of accurate and reliable correlations. The last 2 decades have seen the emergence of large and powerful data bases dedicated to providing a comprehensive treatment of components and mixtures properties as well as more modest, simple and fast systems associated with process simulators. The later type accumulates pure component data (critical constants, normal points, binary interaction parameters, etc.) in order to be able to predict single component and mixed stream properties. The emphasis in the design of the physicochemical package associated with steady state process simulators is efficient computation, flexibility and easiness to update data. Thus, the structure of memory used is of paramount importance in the overall performance of the simulator. Conclusions and Significance—The Physicochemical Properties Package presented here is based on a collection of executable versions of traditional property estimation programs. The system is supported by a physicochemical data base whose structure is defined and maintained by a data base management system of the network type. The structural flexibility achieved by this configuration assures a continuous updating of components as well as of the methods to be used for property estimation

A steady state process simulator with a DBMS (SIMBAD)

Abstract The information handling capability of Data Base Management Programs, together with heat and mass balances programs, has given rise to a new generation of chemical processes simulators. This new generation combines versatility and reliability in the handling of information, with software versions which are both powerful and precise. SIMBAD/INGAR is such a kind of program, highly versatile and able to handle an unlimited variety of chemical components.

Simbad: a process simulator linked to a DBMS—II. the structure of memory

Abstract A network type Data Base Management System is used to support the data structure of a modular-sequential, steady state process simulator. The DBMS of a standard CODASYL type is based on the definition of records and the set relationships between an owner and a member record. The structure defined, or SCHEMA, responds to the way data is stored and used during the simultations in order to minimize access time, while maintaining flexibility. An example is developed to illustrate the way data is linked for a particular process application.

A Semantic Web-Based Architecture to Support Product Data Management Systems

The distributed, dynamic and disparate nature of the information in supply chains is a major obstacle to gather the dispersed information required for the function of an enterprise. This obstacle affects the product data managementpsilas functionality and capability. However, the recent advance in semantic Web technologies gives the opportunity to overcome it. This contribution proposes a semantic Web-based architecture that supports the formulation of queries about the structure of products whose components are manufactured by different nodes of a supply chain that apply the concept of collaborative product development. The integration of different sources of information is achieved by means of a common vocabulary defined by an ontology, but locally keeping data management in each node of the supply chain.

Information logistics for supply chain management within process industry environments

Abstract This contribution proposes the design of an ontology that provides the foundations for the specification of information logistics processes in extended supply chains associated to process industries. The proposed ontology includes concepts and relationships that are necessary to formally describe, measure and evaluate a supply chain (SC), thus simplifying the visualization and analysis of networks. A SC ontology is a first step towards achieving a standard description of SC design and management processes.