Towards the construction of workflow-suitable conceptual modelling techniques

Despite their high-level and graphical nature, workflow specifications require a significant amount of implementation detail — for example application programming interface, database access and programming mechanisms for information flow — for a more comprehensive validation than is currently possible. This is currently recognized as a deficiency in workflow conceptualization. Although conceptual modelling techniques are available which are expressive, comprehensive and precise enough, we believe, their concepts and features are not specialized enough for workflow domains. In this paper, we offer a comparative insight into techniques which characterize different aspects and approaches of workflow specifications. These are: structured process modelling, object-oriented modelling, behavioural process modelling and business-oriented modelling. In particular, we determine gaps for workflows capturing operational business transaction processing, for example those of insurance claims, bank loans and government-related registration. For technique construction, we describe five workflow suitability principles.     

Developing a Theory to Explain the Insights Gained Concerning Information Systems and Business Process Behaviour: The ASSESS-IT Project

Business Process (BP) literature promotes the value of business processes as essential gearwheels that help organisations to reach their goals. Similarly, many process design approaches claim that information technology is a major enabler of business process, a view also shared by the Information Systems (IS) community. Despite this, BP and IS approaches do not provide clear guidance on how to coordinate the design of BP and IS. Nor is any indication of which modelling techniques could be used to detect and design IT opportunities within a business process context given.The ASSESS-IT project examined this domain and proposed the use of simulation techniques to achieve BP and IT integration. The outcome of this project gave indication that depicting the dynamic behaviour of IS could be very helpful for BP modellers to predict the impact that the insertion of IS may have on organisational processes. This paper proposes a simulation framework to depict IS behaviour within a BP simulation model, namely BPS/ISS, and tests it using the case study that was part of the ASSESS-IT project.     

Student modelling in intelligent tutoring systems

Student modelling is a special type of user modelling which is relevant to the adaptability of intelligent tutoring systems. This paper reviews the basic techniques which have been used in student modelling and discusses issues and approaches of current interest. The role of a student model in a tutoring system and methods for representing information about students are discussed. The paper concludes with an overview of some unresolved issues and problems in student modelling.Electric Brain Company     

A geoprocessing workflow system for environmental monitoring and integrated modelling

Environmental information infrastructure benefits from mainstream information technologies including workflow and service technologies. These technologies allow distributed geoprocessing algorithms, models, data, and sensors to be accessed through Web Services, which later can be chained together to support environmental monitoring and integrated modelling. Existing approaches on integrated environmental modelling, such as OpenMI, have advantages in enabling interoperability between modelling components. It is possible to integrate both of them to take the best from both approaches. The paper introduces the design and implementation of a geoprocessing workflow tool, named GeoJModelBuilder, which is able to integrate interoperable Sensor Web, geoprocessing services, and OpenMI-compliant model components into workflows. In this way, sensors, data, geoprocessing functions, and models could be integrated in a flexible, reusable, interoperable, and user-friendly way. The system has been published as an open source software and illustrated in cases on environmental monitoring and integrated modelling.     

Participatory land use modelling,pathways to an integrated approach

The increasing adoption of land use models in planning and policy development highlights the need for an integrated approach that combines analytical modelling techniques with discursive ‘soft-science’ methodologies. Recent scientific contributions to the discipline have tended to focus on analytical problems such as statistical assessment of model goodness of fit through map comparison techniques, while the problem of integrating stakeholder information into land use models has received little attention. Using the example of a land use model developed for the Guadiamar basin in South West Spain, location of the emblematic Doñana natural area, an integrated methodology for participatory calibration and evaluation of model results is presented which combines information from key stakeholders across a range of sectors with analytical model calibration techniques. Both discursive and analytical techniques are presented side by side to demonstrate that including participatory approaches is likely to improve both calibration results and model applicability. Integration of participatory methods into land use models is more likely to be successful if stakeholders are selected carefully so as to make best possible use of their time and knowledge, and are involved in the modelling process from the beginning of the project cycle.     

Bridging the gap between business models and system models

This paper discusses links that may be made between process models and Unified Modelling Language (UML) software specification techniques, working from an argument that the whole complexity of organisational activity cannot be captured by UML alone. The approach taken is to develop a set of use cases, which would be capable of providing information support to a pre-defined organisational process. The nature of the thinking, which is necessary to derive the use cases, is outlined using the pre-defined process as a case study. The grouping of transactions and state changes into Use Cases is shown to require design choices, which may vary between particular organisational contexts. Conclusions are drawn about the direction of further investigation of links between process modelling and UML.     

一元化特征建模技术研究

特征建模是实现ＣＡＤ／ＣＡＭ以及并行工程中信息集成的键。一元化征建模技术融特征设计和特征识别两者一体，设计阶段的初始设计特征进入应用领域后，经过特征识别器表成领域专用特征。     

Integrated parametric multi-level information and numerical modelling of mechanised tunnelling projects

This paper presents a concept for parametric modelling of mechanized tunnelling within a state of the art design environment, as the basis for design assessments for different levels of details (LoDs). To this end, a parametric representation of each system component (soil with excavation, tunnel lining with grouting, Tunnel Boring Machine (TBM) and buildings) is developed in an information model for three LoDs (high, medium and low) and used for the automated generation of numerical models of the tunnel construction process and soil-structure interaction. The platform enables a flexible, user-friendly generation of the tunnel structure for arbitrary alignments based on predefined structural templates for each component, supporting the design process and at the same time providing an insight into the stability and safety of the design. This model, with selected optimal LoDs for each component, dependent on the objective of the analysis, is used for efficient design and process optimisation in mechanized tunnelling. Efficiency and accuracy are further demonstrated through an error-free exchange of information between Building Information Modelling (BIM) and the numerical simulation and with significantly reduced computational effort. The interoperability of the proposed multi-level framework is enabled through the use of an efficient multi-level representation context of the Industry Foundation Classes (IFC). The results reveal that this approach is a major step towards sensible modelling and numerical analysis of complex tunnelling project information at the early design stages.     

DISCRETE AND CONTINUOUS MODELS

Abstract

The growing influence of digital computing in systems modelling and simulation is leading to an increase in the use of discrete mathematical structures for describing models. While it is generally recognized that discrete methods and classical continuous methods both provide valuable tools for modelling, strong biases exist which depend on the modelling techniques that are traditional within specific disciplines. The choice of a modelling approach sometimes reflects the background of the model builder more strongly than it reflects the character of the problem to be solved. Since continuous methods have played the dominant role in scientific education, there are aspects of discrete modelling techniques and their relationship to continuous methods that are not widely recognized. The purpose of this article is to discuss some of these issues in order to dispel common criticisms of discrete techniques which are the result of unfamiliarity with discrete styles of mathematical thinking and a tendency to underestimate the degree of abstraction used in continuous approaches.     

BIM extension for the sustainability appraisal of conceptual steel design

Contemporary advancements in Information Technology and the efforts from various research initiatives in the AEC industry are showing evidence of progress with the emergence of building information modelling (BIM). BIM presents the opportunity of electronically modelling and managing the vast amount of information embedded in a building project, from its conception to end-of-life. Researchers have been looking at extensions to expand its scope. Sustainability is one such modelling extension that is in need of development. This is becoming pertinent for the structural engineer as recent design criteria have put great emphasis on the sustainability credentials in addition to the traditional criteria of structural integrity, constructability and cost. With the complexity of designs, there are now needs to provide decision support tools to aid in the assessment of the sustainability credentials of design solutions. Such tools would be most beneficial at the conceptual design stage so that sustainability is built into the design solution starting from its inception. The sustainability of buildings is related to life cycle and is measured using indicator-terms such as life cycle costing, ecological footprint and carbon footprint. This paper proposes a modelling framework combining these three indicators in providing sustainability assessments of alternative design solutions based on the economic and environmental sustainability pillars. It employs the principles of feature-based modelling to extract construction-specific information from product models for the purposes of sustainability analysis. A prototype system is implemented using .NET and linked to the BIM enabled software, Revit Structures™. The system appraises alternative design solutions using multi-criteria performance analysis. This work demonstrates that current process and data modelling techniques can be employed to model sustainability related information to inform decisions right from the early stages of structural design. It concludes that the utilized information modelling representations – in the form of a process model, implementation algorithms and object-based instantiations – can capture sustainability related information to inform decisions at the early stages of the structural design process.     

Container spaces and functional features for top-down 3D layout design

Although there have been many advances in computer-aided modelling techniques and representations of mechanical parts, there are areas where exact modelling is a handicap. One of these is 3D layout design. Here, simpler models are useful for initial design sketches to verify kinematic behaviour and organise product structure before the detailed component design phase begins. A commitment to exact, or close approximational geometry too early can imply a commitment to form before functionality has been finalised. This paper describes a system for top-down 3D layout design based on simple conceptual elements which can be used as a basis for visualisation, discussion, definition of product structure and kinematic functionality in the conceptual design phase before the embodiment or detailing begins. This tool forms a bridge between the abstract nature of the conceptual design phase and the geometric nature of the embodiment phase. The 3D layout module uses design spaces with simple geometry and kinematic connections to represent a product. The design spaces act as containers or envelopes within which the final component design is to be realised. The kinematic connections allow the behaviour of the product to be simulated to gain more information (such as overall component dimensions and areas of potential collisions) for the detailed design phase. In addition the paper describes the design process based on the proposed 3D layout design system and contrasts this with the traditional design process. An industrial case study is presented to illustrate the following advantages of the proposed approach: (i) the design process proceeds faster because unnecessary layout parameter and constraint modifications are avoided since kinematic functionality verification precedes the detail design, (ii) the design process can produce better designs since alternative solution principles can be explored early in the design process. Theoretical issues are discussed concerning kinematic constraint inheritance during design space decomposition and concerning computer support for non-rigid design spaces.     

Intelligent support for systems development: The notion and the issues

Enterprise modelling and information systems modelling have traditionally utilized techniques developed in the earlier disciplines of systems analysis and operational analysis. However, these tools have proved insufficient even for information systems modelling and their inadequacies make them less than ideal for enterprise modelling. Furthermore, it has proved difficult to integrate the techniques into a uniform framework representation. Extensive research since the early 1980s has produced support tools for information systems engineering in the academic sector which have generally failed to reach widespread commercial use. Commercially developed integrated support systems aimed at enterprise modelling and information system modelling use traditional techniques, with a lack of formalism. The purpose of this paper is to introduce a technique which overcomes the major inadequacies and which provides an integrating framework to represent both the information and the processing, at enterprise and systems modelling levels of abstraction. The technique is based on the use of a transition network, but extended to represent enterprise and system models in a meaningful way. The use of an intelligent repository, with associated processing of the formally defined requirements, specification and design statements, is novel, and provides the additional support to make the technique amenable to handling the design process from informal to formal specification. The use of a graphical user interface, linked directly to the deductive system and repository, ensures intuitive ease of use.     

Graph rewriting systems for the entity-relationship approach

Sequential graph rewriting systems are proposed as a meta-level formalism providing the concise and sound definition of different ER diagram languages. These rewriting systems can be used to define ER-based approaches for various DB modelling subtasks like schema design, evolution and integration. In addition, they are a natural choice for syntax directed ER CASE workbenches. In particular, by using specialized ER graph rewriting systems as meta input for CASE tools, the resulting tool behavior can be guided and controlled. Moreover, grammar driven modelling tools can be easily adapted for the needs of a particular enterprise or software factory without superimposing a particular ER dialect on the end users. Additional benefits result from the use of ER graph rewriting systems as a comparison framework for the continuously enlarging set of ER dialects.

The presentation includes material on the ER graph rewriting formalism, i.e., the actual tool, as well as an introduction to some formal graph rewriting prerequisites. An exemplary application, in particular ER graph generation, is used to clarify the underlying formal concepts.     

Protocol modelling: A modelling approach that supports reusable behavioural abstractions

We describe a behavioural modelling approach based on the concept of a “Protocol Machine”, a machine whose behaviour is governed by rules that determine whether it accepts or refuses events that are presented to it. We show how these machines can be composed in the manner of mixins to model object behaviour and show how the approach provides a basis for defining reusable fine-grained behavioural abstractions. We suggest that this approach provides better encapsulation of object behaviour than traditional object modelling techniques when modelling transactional business systems. We relate the approach to work going on in model driven approaches, specifically the Model Driven Architecture initiative sponsored by the Object Management Group. Communicated by August-Wilhelm Scheer Ashley McNeile is a practitioner with over 25 years of experience in systems development and IT related management consultancy. His main areas of interest are requirements analysis techniques and model execution and in 2001 he founded Metamaxim Ltd. to pioneer new techniques in these areas. He has published and presented widely on object oriented development methodology and systems architecture. Nicholas Simons has been working with formal methods of system specification since their introduction, and has over 20 years experience in building tools for system design, code generation and reverse engineering. In addition, he lectures on systems analysis and design, Web programming and project planning. He is a co-founder and director of Metamaxim Ltd.     

User modelling for adaptive computer systems: a survey of recent developments

User modelling is becoming an important sub-area of Artificial Intelligence with both theoretical and practical consequences. The theoretical foundations of user modelling are to be found in key areas of AI, such as knowledge representation and plan recognition, while its practical applications impinge on the construction of intelligent user interfaces and adaptive systems. This paper provides a survey of current work in user modelling. The paper begins by distinguishing between AI approaches, which are the subject of this survey, and those of HCI (Human-Computer Interaction) and then considers the major issues in user modelling such as: types of user modelling system, the sorts of information modelled, how the information is acquired, represented and used. The paper concludes by examining some of the more problematic aspects of user modelling as well as indicating areas for future research.     

Communicative action-based business process and information systems modelling with DEMO

Abstract. Abstract. The field of communicative action-based modelling of business processes and information systems has attracted more and more attention in recent years. Inspired by the seminal work of Winograd and Flores, researchers have proposed several modelling approaches. In this article we discuss communicative action-based modelling approaches in general and the DEMO (dynamic essential modelling of organizations) approach in particular. Besides establishing the theoretical foundations of this modelling approach, we also apply DEMO to a case study, and we discuss how the resulting models can be used for information systems design and business process optimization.     

A comparison of neural network,evidential reasoning and multiple regression analysis in modelling bridge risks

Artificial neural network (ANN), the evidential reasoning (ER) approach and multiple regression analysis (MRA) can all be utilized to model bridge risks, but their modelling mechanisms and performances are quite different and therefore need comparison. This study compares the modelling mechanisms of the three alternative approaches and their performances in modelling a set of bridge risk data. It is found that ANN outperforms the ER approach and MRA for the considered case study. The reason for this is analyzed. The advantages and disadvantages of the three alternative approaches are also compared.     

Modelling polyhedral solids bounded by multi-curved parametric surfaces

Since the beginning of geometric modelling as a field of CAD a decade ago, the methods for interactive design of solid objects and interactive design of free-formed surfaces (of degree three and higher) were developed along parallel yet disjoint lines. One led to the development of techniques for representing and manipulating the shape of polyhedral solids bounded mostly by planes, while the other led to the development of techniques for the mathematical representation of curved surfaces, without paying attention to their combination into volumetric solids. Though the need for integrating solid object modelling with surface modelling for the design of such artefacts as machine parts, aircraft, cars and ships has been widely recognized, there is so far no single modelling system which provides such capabilities in a general way.An integrated solids modelling system for representing and manipulating polyhedral objects bounded by bicubic parametric surfaces is presented. Its basic capabilities include the representation of solids through a surface-based model, such that the surface underlying any face can be replaced by another surface that has been modelled independently. Other functionalities include scaling, rotation and translation of shapes and their pairwise combination into more complex shapes by means of spatial set operators.     

Combined Petri net modelling and AI-based heuristic hybrid search for flexible manufacturing systems—part II. Heuristic hybrid search

This two-part paper presents modelling and scheduling approaches of flexible manufacturing systems using Petri nets (PNs) and artificial intelligence (AI)-based heuristic search methods. In Part I, PN-based modelling approaches and basic AI-based heuristic search algorithms were presented. In Part II, a new heuristic function that exploits PN information is proposed. Heuristic information obtained from the PN model is used to dramatically reduce the search space. This heuristic is derived from a new concept, the resource cost reachability matrix, which builds on the properties of B-nets proposed in Part I. Two hybrid search algorithms, (1) an approach to model dispatching rules using analysis information provided by the PN simulation and (2) an approach of the modified stage-search algorithm, are proposed to reduce the complexity of large systems. A random problem generator is developed to test the proposed methods. The experimental results show promising results.