Showing papers on "Process modeling published in 1992"

Process modeling

Abstract: • Business process reengineering-the redesign of an organization's business processes to make them more efficient. • Coordination technology-an aid to managing dependencies among the agents within a business process, and provides automated support for the most routinized component processes. * Process-driven software development environments-an automated system for integrating the work of all software related management and staff; it provides embedded support for an orderly and defined software development process. These three applications share a growing requirement to represent the processes through which work is accomplished. To the extent that automation is involved, process representation becomes a vital issue in redesigning work and allocating responsibilities between humans and computers. This requirement reflects the growing use of distributed , networked systems to link the interacting agents responsible for executing a business process. To establish process modeling as a unique area, researchers must identify conceptual boundaries that distinguish their work from model-ing in other areas of information science. Process modeling is distinguished from other types of model-ing in computer science because many of the phenomena modeled must be enacted by a human rather than a machine. At least some mod-eling, however, in the area of human-machine system integration or information systems design has this 'human-executable' attribute. Rather than focusing solely on the user's behavior at the interface or the flow and transformation of data within the system, process model-ing also focuses on interacting behaviors among agents, regardless of whether a computer is involved in the transactions. Much of the research on process modeling has been conducted on software development organizations , since the software engineering community is already accustomed to formal modeling. Software process modeling, in particular , explicitly focuses on phenomena that occur during software creation and evolution, a domain different from that usually mod-eled in human-machine integration or information systems design. Software development is a challenging focus for process modeling because of the creative problem-solving involved in requirements analysis and design, and the coordination of team interactions during the development of a complex intellectual artifact. In this article, software process modeling will be used as an example application for describing the current status of process modeling, issues for practical use, and the research questions that remain ahead. Most software organizations possess several yards of software life cycle description, enough to wrap endlessly around the walls of project rooms. Often these descriptions do not correspond to the processes actually performed during software …

A hybrid neural network‐first principles approach to process modeling

Abstract: A hybrid neural network-first principles modeling scheme is developed and used to model a fedbatch bioreactor. The hybrid model combines a partial first principles model, which incorporates the available prior knowledge about the process being modeled, with a neural network which serves as an estimator of unmeasuredprocess parameters that are difficult to model from first principles. This hybrid model has better properties than standard “black-box” neural network models in that it is able to interpolate and extrapolate much more accurately, is easier to analyze and interpret, and requires significantly fewer training examples. Two alternative state and parameter estimation strategies, extended Kalman filtering and NLP optimization, are also considered. When no a priori known model of the unobserved process parameters is available, the hybrid network model gives better estimates of the parameters, when compared to these methods. By providing a model of these unmeasured parameters, the hybrid network can also make predictions and hence can be used for process optimization. These results apply both when full and partial state measurements are available, but in the latter case a state reconstruction method must be used for the first principles component of the hybrid model.

Planning and analysis of construction operations

Abstract: Construction Processes. Line-of-Balance Models. Queueing Systems. Method Productivity Delay Method. Process Modeling Concepts. Building Process Models. System Definition. Extended Modeling Concepts. Modeling Work Task Durations. Simulation. Typical Repetitive Processes. Building Construction Models. Heavy Construction Models. Sensitivity Analysis. Noncyclic Networks. Appendices. Problems. Bibliography. Index.

Object-oriented and conventional analysis and design methodologies

Abstract: Three object-oriented analysis methodologies and three object-oriented design methodologies are reviewed and compared to one another. The authors' intent is to answer the question of whether emerging object-oriented analysis and design methodologies require incremental or radical changes on the part of prospective adopters. The evolution of conventional development methodologies is discussed, and three areas-system partitioning, end-to-end process modeling, and harvesting reuse-that appear to be strong candidates for further development work are presented. >

Towards a Reference Framework for Process Concepts

Abstract: This paper discusses the importance of process support for business activities. A reference framework for process concepts and technology support is sought. The general requirements and properties of the process domain are first discussed. Then, four process sub-models are presented to describe activities, products, tools and organisations, respectively. Five process model phases are also introduced, as well as meta-processes and related human roles to handle process models and their transformations. The process concepts are applied to a bank example.

Enterprise Information Modeling and Model Integration in Carnot

Abstract: This paper describes a method for integrating separately developed information models The models may be the schemas of databases, frame systems of knowledge bases, domain models of business environments, or process models of business operations The method achieves integration at a semantic level by using an existing global ontology to develop semantic mappings among resources and resolve inconsistencies Our method is incorporated in a graphical integration tool The integrated models provide a coherent picture of an enterprise and enable its resources to be accessed and modified coherently

System and method for process modelling and project planning

Abstract: Enables the flexible handling of time, iteration and resource type as variables. For example, project/process simulation tool defines an activity; defines alternative resources required to commence the activity; determine availability of the alternative resources; and varies a duration of the activity based on the availability of the alternative resources. According to another aspect, a modelling process is a computer, provided for including: supplying a modeling program having a plurality of predefined stages of execution which collectively define a transfer function of an activity within a network; defining a plurality of user supplied programming statements, each provided with a label indicative of at least one of the stages of execution; and, causing the modeling program, to execute the user supplied programming statements, each immediately followed by a stage of execution indicated by the associated label.

Object-oriented approaches for integrated engineering design systems

Abstract: The development of computer‐integrated design systems requires formal models of engineering design. Object‐oriented approaches promise to have a major impact in this area. Two types of engineering design models that could be implemented using an object‐oriented approach are product models, which describe the physical entities that are designed, and process models, which describe design processes. The main difference between these two models is whether the objects implement physical entities or design activities. A general discussion of models for engineering design is presented, followed by more detailed discussion of both product and process models. Object‐oriented concepts are summarized and object‐oriented implementation of product and process models is reviewed. Each implementation consists of objects that bind data and procedures into a single package. The paper then considers how the object‐oriented approach helps to unify product and process models.

A general semiconductor press modeling framework

Abstract: A general semiconductor process modeling framework is presented. The framework encompasses, first, a methodology for the description of any manufacturing process using state and state transformation information and, second, a conceptual process model that distinguishes between and defines terms for the state information and state transformations involved in integrated circuit fabrication. This modeling methodology and conceptual semiconductor process model aid in the understanding of fabrication processes, provide a formalism for the description of processes, help to guide the development of process flow languages and representations, and support a number of process-related activities, including process design and process control. >

Model management systems: a survey

Abstract: This paper provides a survey of model management literature within the mathematical modeling domain. The first part of the survey is a review and a summary of the literature. After giving some basic definitions of modeling, modeling life cycle, and model management, two representative algebraic modeling languages followed by three approaches to modeling are introduced. These approaches are database, graph-based, and knowledge-based. The discussion is followed by a review of two specialized model management systems. The second part of the survey is a categorization of various modeling systems based on the modeling functions they provide and some of their features. These functions include life cycle support and model base administration. The degree of model independence provided by model management systems and the implemented environment systems is also summarized. The last part of the paper provides directions for future research.

Case*Method: Function and Process Modelling

Abstract: From the Publisher: business functions and a wealth of realistic examples illustrating function and process modelling in practice. It provides clear guidelines for when to use each technique and a comprehensive glossary of all important terms. Features Easy-to-learn techniques for modelling key business functions, processes, and events. A wealth of realistic examples illustrating function and process modelling in practice. Clear guidelines for when to use each technique. A comprehensive glossary of all important terms.

Development of an appropriate resource information system to support agricultural management at farm enterprise level (ARIS).

Abstract: This thesis describes development of and experimentation with a prototype of an appropriate resource information system that improves decision making processes in farm management The system includes a geographic information system with a powerful process model that forms a decision support system for land use planning, monitoring and evaluation at farm enterprise level. The land use planning sub-system uses a new concept and supports planning at tactical and operational levels. It consists of a crop growth simulation model that accurately estimates the productivity of each feasible land use, a linear programming model that integrates the physical and socioeconomic information and designs the best suitable plan that maximizes the profit of the system under a given set of constraints (tactical plan), ad a spatial decision model that translates the tactical plan into an actual operational plan. The system illustrates the importance of process models in the integration of information from various disciplines and sources into management decisions, and the application of geographic information systems in support of multiple objective decision problems.

Business process redesign and information architecture: establishing the missing links

Abstract: Business Process Redesign (BPR) and Information Architecture (IA) have been recognized as high organizational priority agenda items in the 1990s. This paper provides tile premise for integrating these two critical issues. A model depicting the relationship between IA and BPR is presented. IA design and BPR share a common focus on business processes and, when properly conducted, IA design should produce a stable information architecture capable of supporting existing as well as improved business processes. Furthermore, selected IA methods and techniques are recommended for possible application in BPR. Future research is suggested concerning the need to validate this BPR and IA relationship and test the appropriateness of applying IA methodologies to BPR.

Rechnergestützte Erstellung verfahrenstechnischer Prozeßmodelle

Abstract: Computer-aided generation of chemical engineering process models. The availability of adequate process models is still the most striking bottleneck for routine application of model-based techniques in process design and operation. The development of knowledge-based software tools to support process modeling is considered an important contribution to a solution of this problem. After a brief summary of the modeling tools offered in current simulator architectures, a future knowledge-based modeling tool is sketched. In addition to the software engineering, the acquisition and formalization of the modeling knowledge – comprising meaningful submodels and generic modeling strategies – is essential for the feasibility of the approach and for the acceptance of a tool. Therefore, these two themes are discussed in considerable detail. Finally, first prototype developments towards a knowledge-based modeling tool are presented.

Developing a model to manage the software maintenance process

Abstract: The authors report on their work to data on a collaborative project which has the objective of improving industrial software maintenance management through the design and introduction of a comprehensive process model. A framework based on their experience of developing and using different types of process models is presented; this approach enables process models to be developed and used by managers in a beneficial manner to meet organizational objectives and improve existing processes. >

Automatic simulation of a robot program for a sequential manufacturing process

Abstract: This paper presents a framework for the design of a hierarchical Simulator of a robotized sequential technological process. The framework employs concepts of discrerte event simulation modelling. The Simulator consists of two layers: the Simulator of a robot and technological process, and the interpreter and planner of robot tasks. A format specification of both layers is presented. The proposed simulation approach is expected to result in significant improvements in the robot task plan generation and in higher efficiency of a technological process.

A process method for the design of “Intelligent” man-machine interfaces: Case study: “The decisional module of imagery”

Abstract: A new concept is appearing in the field of man-machine interaction: the design of “intelligent” interfaces. The aims of this article are threefold, first to show what an “intelligent” interface is and present a five-step design process for such an interface-specifically: (1) man-machine system analysis; (2) operator, task, and process modeling: (3) specifying those assistance tools that form an “intelligent” interface; (4) realization of the assistance tool; and (5) evaluation. The second part describes the structure of an “intelligent” interface, called D.M.I. (Decisional Module of Imagery), which is currently being developed. The final part explains the D.M.I.’s development, using the five process steps outlined above.

Products, processes and metrics

Abstract: The paper reviews developments in the arena of software engineering product metrics, with special reference to system architecture metrics. Some of the weaknesses of current approaches are examined, in particular the very weak notion of process embodied by a product metric. It is argued that the consequence of this oversight is uncertainty in the application and interpretation of metrics. This in turn has led to a slow uptake of product metrics by the software industry. The paper then demonstrates, by means of a simple design metric example, that the application of concepts from the area of software process modelling to product metrics can help overcome many of these deficiencies; it also results in quantitative process models that have potential for the design and construction of software tools and environments.

Emulating human process control functions with neural networks

Abstract: This investigation demonstrates that neural networks can perform some of the tasks in controlling complex systems that have been traditionally reserved for humans. Neural networks can be used to fuse different types of knowledge from many sources into a general process model. This technique allows process models to be formed for systems that are too complex to be modeled with conventional tools. By adding relatively few local measurements, a general process model can be calibrated into a numerically accurate local model of the process. This local model can then used for steady-state process optimization. The architectures and training techniques needed to produce neural networks capable of performing these functions are discussed. This technology was applied to the control of a complex system--a grain harvesting combine. Field tests of the harvesting process under neural network control demonstrated that the controller was robust and capable of exceeding the performance of expert human operators.

Mathematical modelling of startup and shutdown operations of process plants

Abstract: In this thesis, the practice of mathematical modelling is investigated. It has long been recognised that process modelling is a very imprecise craft. Because of the difficulty in representing complex physical phenomena as simple mathematical abstractions, modelling has evolved as a series of adhoc, subjective steps. The impact of this situation has often been the lack of credible and reliable mathematical models for optimal process design and operation. The goal of this work was therefore to search for a systematic methodology for modelling which will conceive models with the desirable attributes of simplicity, accuracy and functionality. While the focus of this thesis is the development of a general modelling methodology, applications of the work are restricted to the modelling of startup and shutdown operations. Because of the complexity and critical impact on plant operation, startup and shutdown transients serve as practical examples where mathematical modelling is of value. A new modelling methodology is proposed in this thesis which features a systematic method for model characterisation. In a two step procedure, a reference model is first built in which few simplifying assumptions are made. All conceivable physical phenomena are included in this model. Perturbation model reduction methods are then employed to identify the essential structure in this reference model. Redundant structure is then omitted from the reference model to produce a low order model with all of the desired attributes. The key feature of this new modelling methodology is that it is systematic and a model is constructed which is commensurate with the modelling objectives. Exploitation of the reference model structure is the mechanism upon which this new methodology is based. A significant portion of this thesis is therefore devoted to the development of perturbation model reduction methods for structure identification. Two major case studies are presented to illustrate the proposed methodology. In the first, a low order model is built for the simulation of the startup of a single stage evaporator process. The second case study involves the modelling of a three stage centrifugal compressor system for prediction of machine surge during shutdown. In both cases, an intimate knowledge of causality with the process and a substantial reduction in model size was achieved by exploiting latent model structure. It was also recognised in this work that knowledge of process structure is of value in other situations. Two additional applications of model structure were investigated in this thesis. In the first the dependence of structure on the process parameters was quantified. The relationship between process parameters and the model structure was then used in a novel design algorithm. In this design method, the process parameters were selected to achieve a specified dynamic performance criteria. The innovative contributions of this work to the field of mathematical modelling include: development of a systematic method for process characterisation; development of structural parameters for the identification of model perturbations within a mathematical model; the development of a continuation algorithm for association of model states with modes and the proposal of a novel process design algorithm based on the exploitation of model structure

Process Modeling using Structured Neural Networks

Abstract: A modeling approach is developed which combines a partial first principles model, incorporating the available prior knowledge about the process being modeled, with a neural network which serves as a non-parametric estimator of unmeasured process parameters that are difficult to model. This hybrid model is superior to standard "black-box" neural network models in that it interpolates and extrapolates much more accurately, is easier to analyze and interpret, and requires significantly fewer training examples. The hybrid network model, when used to model a fedbatch bioreactor, gives estimates of the unobserved process parameters and can be used to make predictions. This approach can also be applied when only part of the state is measured by using a state reconstruction method for the first principles component of the hybrid model.

Process modelling: a critical analysis

Abstract: This paper uses a software development environment construction case study as a framework for a critical analysis of software process modelling. It outlines a research agenda based on this analysis.