Knowledge representation of the software architecture design process based on situation calculus

Software architecture design is an interactive, complex, decision‐making process. Such a design process involves the exploration, evaluation, and composition of design alternatives. Increasingly, new computer‐aided tools are available to help designers in these complex activities. However, these tools do not know how design is actually done, in other words, by means of which design activities the final artefact was obtained. In fact, the architectural design knowledge exclusively rests in the mind of designers, and there is an urgent need to move it, as much as possible, to a computer‐supported environment that enables the capture of this type of knowledge. This contribution addresses this need by introducing a model for capturing how products under development are generated and transformed along the software architecture design process. The proposed model follows an operational perspective, where architectural design decisions are modelled by means of sequences of operations that are applied on the design products. Situation calculus is used to formally express the existence of an object in a given state of a design process. In addition, this formalism allows us expressing without ambiguities when an operation can be performed in a specific state of the design process.     

Supporting communication and cooperation in distributed representation for adaptive design

Different types of graphs has been successfully used to represent designs at different stages of the design process. Changes to a model representing a design during the process can be modelled by applying graph transformations. In many real life design tasks the changes/updates can be carried out simultaneously on different parts of the design. Hence a model based on graph transformations is coupled with a multiagent paradigm to enable the parallelisation of these transformations to mimic the real life approach. In this paper a hypergraph representation and transformation model is used as a basis for building a multiagent system supporting distribution and adaptation in computer aided design. This representation can be applicable throughout the lifecycle of the design. It is based on research in formal language theory, like graph grammars, and distributed models including multiagent systems. The motivation for the work presented here is given and possible applications are described. The application of the theoretical results in a graph distribution toolkit proposed as a multiagent framework is also considered. To assure the efficiency of the system it should be implemented as a parallel multiagent system. The hypergraph distribution and partial replication, allowing for its parts to be managed by agents, is also presented. The approach is illustrated by a case study from the domain of building design, where it is used to represent, modify and maintain building information.     

模具企业订单文档管理系统的实现

分析我国模具企业的业务流程以及生产过程中存在的问题,提出基于订单和产品的管理系统模型,并根据此模型实现了订单文档管理系统。系统管理模具从订单到交货的整个生命周期,缩短了产品设计周期,提高了产品质量,增强了企业竞争力。     

Computer-aided RCM-based plant maintenance management system

In most of the industries, classical reliability-centered maintenance (RCM) is employed to decide the maintenance strategies using reliability data without having adequate interaction with the design and operational systems. This means that the RCM process will be conducted with no or limited access to the design and operational data/knowledge. Commonly, the developed maintenance strategies are implemented and managed within the computerized maintenance management system (CMMS), which is usually separate from the RCM automated environment. This paper presents the detailed system design and mechanism of improved RCM process as integrated with CMMS. The proposed solution is integrated with design and operational systems and consolidates some successful maintainability approaches to formulate an effective solution for optimized plant maintenance. The major components of the enhanced RCM process are identified and a prototype system is implemented as integrated with the various modules of the adopted CMMS (MAXIMO™). A case study is used to show the effectiveness of the proposed RCM-based CMMS solution in optimizing plant maintenance over the traditional approaches.     

From process logic to business logic—A cognitive approach to business process management

The unpredictability of business activities means that business process management should provide a way to adapt to change. The traditional workflow approach, based on predefined process logic, offers little support for today's complex and dynamic business environment. Therefore, a cognitive approach is proposed to help manage complex business activities, based on continuous awareness of situations and real-time decisions on activities. In this approach, the business environment is seen as capturing events that occurred and the state of tasks and resources; business logic involving process routing, operational constraints, exception handling and business strategy is used to determine which actions are appropriate for the current situation. By extending process management from process logic to business logic, the methodology offers flexibility, agility and adaptability in complex business process management.     

Safety-based availability assessment at design stage

The availability of a system or equipment is one of the crucial characteristics that measures the customer satisfaction and strongly influences his final choice decision between concurrent products. The aim of this work is to provide an approach to improve the products availability assessment by taking into account the safety criteria by considering the use situations at design stage. Our work focuses on the routine design of complex products. The availability is often simply estimated considering reliability and maintainability. Basically, the intrinsic availability is the probability that it is operating satisfactorily at any point in time when used under conditions stated by design specifications. The time considered includes operating time and active repair time. Thus, intrinsic availability excludes from consideration all other times in the product lifecycle such as: accident management time, storage time, administrative time or logistic time. But many studies show that the loss of availability performance is also due to accidents that occur in different unforeseeable utilization situations. This engenders stops of the system to ensure the users safety according to standards recommendations. In this purpose, we consider the structural product architecture and the different use cases that correspond to the operational states and downtimes due to stop events that may happen during the utilization like failures, maintenance tasks and accidents. Then, we propose a product behavioral analysis including the use cases to describe interactions between the product and users or maintenance operators. We use Markov chains to model the use cases corresponding to operating time (OT), maintenance time (MT) and preparing time after accidents (RT). Then these three parameters are considered to specify a generic approach to improve the availability assessment. Such an approach provides the traceability of the product behavior along its lifecycle. In this way, the main causes of stop can be identified and this may guide the designer for improving the availability of the product future versions. To validate our approach, an application is presented considering a printing line. The comparison of our simulation considering an industrial case study shows a good agreement about the influence of safety on the availability.     

Model-free adaptive control design using evolutionary-neural compensator

It is well-known that conventional control theories are widely suited for applications where the processes can be reasonably described in advance. However, when the plant’s dynamics are hard to characterize precisely or are subject to environmental uncertainties, one may encounter difficulties in applying the conventional controller design methodologies. In this case, an alternative design is a model-free learning adaptive control (MFLAC), based on pseudo-gradient concepts with compensation using a radial basis function neural network and optimization approach with differential evolution technique presented in this paper. Motivation for developing a new approach is to overcome the limitation of the conventional MFLAC design, which cannot guarantee satisfactory control performance when the nonlinear process has different gains for the operational range. Robustness of the MFLAC with evolutionary-neural compensation scheme is compared to the MFLAC without compensation. Simulation results for a nonlinear chemical reactor and nonlinear control valve are given to show the advantages of the proposed evolutionary-neural compensator for MFLAC design.     

Understanding design activities through computer simulation

In this paper, a new experimental approach – computer simulation – is introduced for understanding design activities and for validating design theories. Following the generic framework of computer simulation, three main components in simulating design activities are introduced: mathematical model, simulation model, and statistical analysis. The mathematical model consists of the design governing equation and Environment-Based Design (EBD), based on which three routes are introduced to look for new design solutions: (1) formulating the design problem differently at the beginning of a design process may get quite different solutions, in which creative design could emerge; (2) extending designer’s knowledge and experience can help generate more candidate solutions, and so increasing the probability of generating a good concept; (3) changing the sequence of design problem decomposition may change product requirements, and thus change the generated design concepts. By viewing mesh generation algorithms as design agents, a computer simulation environment is used to study design activities. Statistical analysis is conducted to validate quantitatively the three routes to new design solutions. The results show that computer simulation is an effective approach to studying design activities.     

A part affordance-based approach for capturing detailed design knowledge

Design knowledge reuse is widely accepted as an effective strategy for designers to develop robust artifacts with less time and lower cost. However, there has been very little research on how to help designers capture detailed design knowledge for reuse. As a result, most detailed design knowledge still has to remain in designers’ memories as tacit knowledge, which can easily get lost due to oblivion or the mobility of designers. Therefore, this paper attempts to develop a part affordance-based approach for externalizing and capturing detailed design knowledge for effective reuse. It first introduces a part model for representing the detailed design-related information. Based on the relational theory for design, the concept, part affordance, is then employed to help designers externalize and capture various lifecycle factors that are implicit in a detailed design. Based on the affordance constraint axiom, a systematic approach is then proposed for deriving tacit design knowledge from captured part affordances through the analysis of extreme working situations. The proposed approach has been implemented as the Design Knowledge-Capturing System (DKCS). A fixture design case has been employed to illustrate the proposed approach.     

Telerobot-enabled HUB-CI model for collaborative lifecycle management of design and prototyping

The HUB-CI model is investigated in a telerobotic system in a client/server network to manage the lifecycle of engineering design and prototyping. The purpose of this platform is to support collaborative engineering design and proof of concept to enhance distributed team collaboration and resource utilization. The suggested platform is exemplified in two collaboration support tools and a physical prototyping platform. Structured Co-Insight Management is developed to support innovative idea exchanges and the consensus decision-making during the design process. Conflict/error detection management helps preventing conflicts and errors during the lifecycle of design and development. Physical collaboration over the network occurs when a team controls the telerobot operation during prototyping and testing in design cycles. A pilot system is implemented with a group project for the design of an electronic circuit (including both hardware and software designs). The functional assessment method is used to compare this platform to other collaborative design tools. The system presented offers unique qualitative advantages as an integrated collaboration support system.     

Traceability and management of dispersed product knowledge during design and manufacturing

Product development processes comprise highly creative and knowledge-intensive tasks that involve extensive information exchange and communication among geographically distributed teams. Due to the geographical and institutional separation between the different systems involved in the product lifecycle, product knowledge sharing is becoming a key issue in the information systems of extended enterprises. This paper addresses the issue and challenges of product knowledge traceability during the product development. The aim of this research effort is to enhance the sharing and use of product knowledge acquired during the development process using traceability information.A standardized approach is proposed to trace and share product knowledge and key constructs to support traceability during the product development process are identified and formalized. This research effort is based on the premise that an important step towards achieving product knowledge sharing is providing traceability across various product knowledge elements that are used in product development phases, i.e. design and manufacturing. Two disjointed but complementary case studies illustrating the benefit of traceability are presented. The potential role of traceability is described, first to support the decision making process during engineering change management (ECM), and second to support product-oriented modelling for knowledge sharing and exchanging to meet the quality requirements. The proposed approach has been implemented using the MEGA Suite tool and applied to each of the case studies and could be integrated to PLM systems currently in use.     

Simultaneous design and control of chemical processes with application to the Tennessee Eastman process

This paper presents a new methodology to integrate process design and control design for chemical processes. The proposed method estimates infinite-time horizon bounds for worst-case scenarios and enforces process feasibility constraints using Structured Singular Value analysis (μ). By using these bounds expensive dynamic optimizations are avoided thus permitting the formulation of a computationally efficient algorithm that is suitable for large-scale systems. The approach was applied to the simultaneous design and control of the Tennessee Eastman process. The effect of different parameters on the resulting process design and control design for this plant were analyzed. The results indicate that an increase of the reactor’s capacity with respect to the currently used value may result in significant cost reduction.     

Conceptual design of industrial process displays

Today, process displays used in industry are often designed on the basis of piping and instrumentation diagrams without any method of ensuring that the needs of the operators are fulfilled. Therefore, a method for a systematic approach to the design of process displays is needed. This paper discusses aspects of process display design taking into account both the designer's and the operator's points of view. Three aspects are emphasized: the operator tasks, the display content and the display form. The distinction between these three aspects is the basis for proposing an outline for a display design method that matches the industrial practice of modular plant design and satisfies the needs of reusability of display design solutions. The main considerations in display design in the industry are to specify the operator's activities in detail, to extract the information the operators need from the plant design specification and documentation, and finally to present this information. The form of the display is selected from existing standardized display elements such as trend curves, mimic diagrams, ecological interfaces, etc. Further knowledge is required to invent new display elements. That is, knowledge about basic visual means of presenting information and how humans perceive and interpret these means and combinations. This knowledge is required in the systematic selection of graphical items for a given display content. The industrial part of the method is first illustrated in the paper by a simple example from a plant with batch processes. Later the method is applied to develop a supervisory display for a condenser system in a nuclear power plant. The differences between the continuous plant domain of power production and the batch processes from the example are analysed and broad categories of display types are proposed. The problems involved in specification and invention of a supervisory display are analysed and conclusions from these problems are made. It is concluded that the design method proposed provides a framework for the progress of the display design and is useful in pin-pointing the actual problems. The method was useful in reducing the number of existing displays that could fulfil the requirements of the supervision task. The method provided at the same time a framework for dealing with the problems involved in inventing new displays based on structured analysis. However the problems in a systematic approach to display invention still need consideration.     

Iterative design and testing within the software development life cycle

The activity of testing begins during system development and spans all subsequent phases. Some system development lifecycles describe testing which is performed after the coding phase, but this may cause the software to be delivered without sufficient testing. In this paper, we present a software system development lifecycle model, called the Test design Stages Processed model (TSP model), in which we emphasize that iterative test design stages should be incorporated at each phase of the software development lifecycle. When a phase is completed, testing of the phase should also be completed at that time. Within this paper we have added unit, integration and system testing processes into BoochÕs micro–design process to generate a new designs and test model. This shows the process of iterative and incremental software development. Comparing this with our model, we explain how the TSP model can be used for developing and testing an object-oriented software system.     

Overview of entity-based integrated design product and process models

The development of computer-integrated systems for engineering design requires models to describe and organize the information and activities involved in design. A product model describes the information created during the design process, and a process model describes the associated design activities. Product and process models can be integrated into a single model. An entity-based approach is one way to carry out this integration. An entity-based integrated model uses product entities and process entities to represent design information and design activities, respectively. The relationships among these entities include organizational, interaction and sequence relationships. Organizational relationships organize entities into hierarchies, interaction relationships characterize the nature of entity interactions, and sequence relationships identify the sequences in which process entities are initiated during the design process. This paper presents an overview of the product and process entities, and the organizational, interaction and sequence relationships of entity-based integrated design product and process models. Formal concepts and notation used to represent these entities and relationships are described using a simple design example. © 1998 Published by Elsevier Science Limited. All rights reserved.     

Toward standardized exchange of plant 3D CAD models using ISO 15926

Plant three-dimensional (3D) computer-aided design (CAD) models typically consist of logical configuration, equipment specifications and ports, and 3D shapes. Because 3D CAD models are used as master information throughout a plant’s entire lifecycle and many stakeholders are involved in such lifecycle, providing a method for sharing plant 3D CAD models among various stakeholders is very important. Standard 15926 from the International Organization for Standardization (ISO 15926) is a family of standards that is intended to support the sharing and integrating of all information during the life of a process plant. Therefore it is important for ISO 15926 to support plant 3D CAD models. In order to address this issue, this study investigates a standardized method to exchange plant 3D CAD models using ISO 15926. Information requirements regarding plant 3D CAD models are established, and then ISO 15926 reference data (classes, attributes, and templates) are extended to cover information requirements. For demonstration of the proposed method, we developed a prototype platform where plant 3D CAD models in ISO 15926 are loaded and retrieved.     

A nonparametric approach to design robust controllers for uncertain systems: Application to an air flow heating system

This paper presents an approach to design robust fixed structure controllers for uncertain systems using a finite set of measurements in the frequency domain. In traditional control system design, usually, based on measurements, a model of the plant, which is only an approximation of the physical system, is first built, and then control approaches are used to design a controller based on the identified model. Errors associated with the identification process as well as the inevitable uncertainties associated with plant parameter variations, external disturbances, measurement noise, etc. are expected to all contribute to the degradation of the performance of such a scheme. In this paper, we propose a nonparametric method that uses frequency-domain data to directly design a robust controller, for a class of uncertainties, without the need for model identification. The proposed technique, which is based on interval analysis, allows us to take into account the plant uncertainties during the controller synthesis itself. The technique relies on computing the controller parameters for which the set of all possible frequency responses of the closed-loop system are included in the envelope of a desired frequency response. Such an inclusion problem can be solved using interval techniques. The main advantages of the proposed approach are: (1) the control design does not require any mathematical model, (2) the controller is robust with respect to plant uncertainties, and (3) the controller structure can be chosen a priori, which allows us to select low-order controllers. To illustrate the proposed method and demonstrate its efficacy, an application to an air flow heating system is presented.     

Re-engineering of the design process for concurrent engineering

According to the requirements of concurrent engineering, three interdependency relationships (uncoupled relationship, coupled relationship and decoupled relationship) between design activities are presented in this paper. And the coupled relationship plays an important role in concurrent product design process. To represent the precedence relationships among design activities, a directed graph is used to describe the design process. And the interdependency relationship between activities is illustrated by a Design Structure Matrix which is the transpose of the accessibility matrix of the corresponding graph. Using the DSM, an algorithm of recognizing the coupled activities during the design process is presented. Moreover, an algorithm to figure out the order levels of activities during the design process is proposed. And both algorithms are illustrated with a die design example.     

Reliability prediction for evolutionary product in the conceptual design phase using neural network-based fuzzy synthetic assessment

Reliability prediction plays an important role in product lifecycle management. It has been used to assess various reliability indices (such as reliability, availability and mean time to failure) before a new product is physically built and/or put into use. In this article, a novel approach is proposed to facilitate reliability prediction for evolutionary products during their early design stages. Due to the lack of sufficient data in the conceptual design phase, reliability prediction is not a straightforward task. Taking account of the information from existing similar products and knowledge from domain experts, a neural network-based fuzzy synthetic assessment (FSA) approach is proposed to predict the reliability indices that a new evolutionary product could achieve. The proposed approach takes advantage of the capability of the back-propagation neural network in terms of constructing highly non-linear functional relationship and combines both the data sets from existing similar products and subjective knowledge from domain experts. It is able to reach a more accurate prediction than the conventional FSA method reported in the literature. The effectiveness and advantages of the proposed method are demonstrated via a case study of the fuel injection pump and a comparative study.     

Adaptive generic product structure modelling for design reuse in engineer-to-order products

In product lifecycle management, the efficiency of information reuse relies on the definition and management of equivalence information between various product data and structure representations. Equivalence information ensures the consistency and traceability of product information throughout the product lifecycle. The sales-delivery process of engineer-to-order (ETO) products presents a great potential for design reuse, i.e. the reuse of previously validated design solutions in the design of new product variants according to customer-specific requirements. A product family data model that focuses on the interdependencies of viewpoints on information will therefore improve the setup of design reuse mechanisms such as modularity. This paper describes the Adaptive Generic Product Structure (AGPS), a dynamic structure-based product family modelling approach that enables the systematic aggregation of product variants and their distinctive components. The purpose of the approach is to capitalize on the expanding component variety developed within previous product variants as early as the sales lead phase of the sales-delivery process, in order to reduce customer-driven design costs and shorten lead-times. An illustrative example based on the aerospace industry is presented.