OPIS: An Object Model–Based Project Information System

Abstract: Future computer-aided project management (CAPM) software will be greatly improved through the technologies of project modeling—the rich, general-purpose representation of the project in the computer—and system integration—the sharing of computer models among applications. Our approach is to achieve system integration by establishing standard models that all applications can adopt and share. This requires a standard data model that specifies the general data-representation approach, a standard domain model that provides a schema or language for representing construction information, and a project model or database for information about a specific project that can be shared among multiple computer applications. This paper reviews these standard models and then describes our prototype integrated system called the object model–based project information system, or OPIS. OPIS uses a shared object–oriented database as the central unifying core of an integrated project planning system that includes an interface to an intelligent CADD program, a plan-generation expert system, an estimating application, and a scheduling application. OPIS demonstrates the feasibility and power of using standard object-oriented project models to achieve CAPM system integration.     

Semantic Enrichment for Building Information Modeling

Significant difficulties remain in exchanging information between building information modeling (BIM) tools. The industry foundation classes (IFC) exchange schema is too generic to capture the full semantic meaning needed for direct use by different construction project stakeholders’ BIM tools. Although BIM standards that prescribe model view definitions (MVD) for domain‐specific exchanges are under development, insufficient semantic definition of exchanges prevents achievement of the full potential of BIM through seamless interoperability. We propose an innovative approach for supplementing an IFC exchange file with semantically useful concepts inferred from the explicit and implicit information contained in the building model. A prototype software was implemented to test the applicability of the approach. It consists of a rule‐processing engine and allows composition of inference rule‐sets that can be tailored for different domains. The tests demonstrate semantic enrichment with precast concrete building models, adding inferred joint, slab aggregation and connection concepts.     

虚拟施工的BIM应用:三大高校合作项目

越来越多的设施业主要求项目组移交竣工BIM模型,以便用于建筑的运营和维护。根据项目要求的不同,业主可能将竣工模型建立与移交的责任指派给总承包商。因此,施工队伍的各成员不但越来越需要熟悉BIM建模软件的应用,还需熟悉利用可靠的设施信息支持完整BIM的必要业务流程。竣TBIM模型的创建,要求承包商首先要基于建筑师、工程师和顾问等设计师所提供的图纸和信息的基础上,创建建筑,结构和设备模型。这要求承包商的组织机构内要有一名人员具备各与专业设计模型相关的技能和知识。一旦设计模型被创建(或重新创建),承包商可将这些模型用于开发施工用的BIM模型。一个完整的施工模型通常包括:成本估算,施工进度计划、冲突检测与分析以及现场物流。业主对设施管理用竣工模型提出新增要求,包括添加运营和维护用的具体数据。本文所述项目旨在为了更好地了解,在为业主实施BIM的项目上,承包商对项目所起作用的复杂性。为实现此目标,三所大学合作建立了数个校际团队,从每所学校各抽调一名学生分配至三个团队的一个,充当BIM商业建筑项目BIM应用里的承包商角色。本文从两个方面汇报项目的挑战和细节:导师——项目组织、学习目标和策略,学生——项目组织、团队合作过程以及策略。     

Validations for ensuring the interoperability of data exchange of a building information model

During the design and construction phases of building projects, domain experts iteratively exchange building information models. One of their goals is to ensure that the requirements and objectives of a proposed project are satisfied. In addition, most building information modeling software currently implements heterogeneous mapping processes in their IFC interfaces that bind their native models to the IFC format. However, such exchanges frequently do not realize intended geometric transformations, project requirements, and required syntactic and semantic conditions in building model data, exacerbating the problem of model integrity and resulting in expensive changes during the construction and operation phases. These problematic issues have been addressed by the development of solid frameworks for validating a building design. This paper surveys six currently available applications for validating building design data and identifies their strengths and weaknesses: The Express Engine's EXPRESSO, the JDSAI™, the EXPRESS Data Manager™, the IFC server ActiveX Component, the IfcDoc, and the Solibri Model Checker^®. We also structured the validation processes into three types of tasks: 1) a syntax check of the assurance of compliance with the IFC schema defined by the EXPRESS language, 2) semantic and syntactic assessment in terms of conformity to model view definitions, which consist of concept modularizations, and 3) the validation of design programming requirements that evaluates regulations, project criteria, owner requirements, and functional performance. The purpose of this survey, based on available software that supports the validation of building model data for these three types of interoperability issues, is to integrate diverse checking approaches, as a basis for improving what are now widely distributed efforts.     

Logic for ensuring the data exchange integrity of building information models

Industry domains require distinct data and structures of building information models developed and tailored for their disciplines. To seamlessly exchange the building information models, Industry Foundation Classes (IFC), which is one of neutral formats, has been broadly used in the architecture, engineering and construction, and facility management industries. Model view definition (MVD), which is one of the IFC sub-schemas used by domain experts and BIM software vendors, consists of IFC-mapped data exchange requirements of each domain and helps software vendors develop IFC import and export features that allow project participants share and exchange BIM model information. Because of the heterogeneous translation processes and structures of IFC interfaces according to model views, their validation is imperative to ensure the integrity of BIM data and maintain a consistent data exchange environment. To accomplish this objective, this paper suggests the new approach to evaluating BIM data in accordance with diverse requirements of MVD. Since MVD entails various types of data exchange specifications, this research study examines their embedded checking rule types and categorizes corresponding implementation scenarios. In addition, this paper involves rule logic and IfcDoc-based BIM data validation developed based on the logical rule compositions of identified rules types and checking scenarios. This approach is expected to support sharing consistent BIM data sets and confirming the quality of received data pertaining to a syntax and semantics of a targeted model view.     

IFC model viewer to support nD model application

Today, building information modelling (BIM) plays a crucial role in the research and development fields of construction information integration and interoperability. This paper, from an information technology point of view, outlines the definition and aims of the “3D to nD Modelling” project, a platform grant-funded project by UK’s British Engineering and Physics Sciences Research Council (EPSRC). It presents a scenario of widening BIM implementation into the overall aspects involved in the whole life cycle of a building project. Industry foundation classes (IFC) as a standard BIM specification has been adopted as a central information repository in order to deliver the integrated building information throughout the nD-driven assessments, evaluation and decision-making. This paper also focuses on the development of an IFC-viewer, which is defined as the holistic interface of the nD modelling tool. The techniques and methods including the auxiliary tools adopted in this development are detailed. This development presents a practical and economic way to reveal and retrieve the information of IFC models inclusively, structurally and visually.     

基于SU-BIM的项目管理平台研究

本文从SKETCHUP 软件和BIM 的特点入手,拟对建设项目采用基于SKETCHUP的建筑信息模型（SU-BIM）平台对工程项目进行辅助管理的可行性进行分析,探讨 SU-BIM在实际工程项目中的应用思路和前景,以期对工程项目基于SU-BIM的管理起到一个探索作用。     

An aerodynamic and aeroelastic experimental study on a sectional and three‐dimensional rectangular tall building

This paper examines the aerodynamic properties of a rectangular tall building with sharp edges. The building has a section aspect ratio B/D = 2.6 and a height aspect ratio H/D = 9, giving in a quite slender prismatic configuration. The study was performed on sectional and three‐dimensional models of the building. The sectional model was tested in a smooth flow condition, and the aerodynamic coefficients of the section were determined. Forces and pressure distributions were measured on the three‐dimensional model to compare with the aerodynamic behavior of the sectional model. Both a rigid (non‐moving) and a moving model of the building were tested to analyze possible aeroelastic effects. Different levels of incoming wind turbulence were tested, since this is a key parameter in the aerodynamic behavior of the rectangular prism. Copyright © 2015 John Wiley & Sons, Ltd.     

Uncertainty propagation of material properties in energy simulation of existing residential buildings: The role of buildings features

Although energy simulation can provide valuable information about building energy behavior, the inaccuracy of input data can undermine the reliability of the results. Despite the vast literature about uncertainty analysis, little is known about the influence of building characteristics on the propagation of uncertainty through the energy simulation models. This study investigates the extent to which uncertain thermal conductivity and specific heat of structural layers affect the annual heating and cooling needs for a set of 144 simplified reference building configurations in three European climates. The analysis is carried out by means of a Monte Carlo technique coupled with TRNSYS hourly simulations. This study points out that the uninsulated residential buildings with a high aspect ratio, a small transparent surface with south exposure and low SHGC are more sensitive in the cooling needs estimation to the propagation of uncertainty in material properties. Similarly, the heating needs precision is greatly reduced when the uncertainty affects the thermal conductivity in uninsulated buildings with a low aspect ratio, a high SHGC and small window size. On the contrary, the uncertainty in specific heat is emphasized in buildings with external insulation having large windows oriented to either east or south and with glazing characterized by high SHGC.     

Integrating Environmental and Economic Sustainability in New Building Construction and Retrofits

The aim of this paper is to grow the literature on methodological approaches directed to find out the most preferable retrofit design solutions for Energy-Efficient Buildings, sustainable from both an environmental and economic point of view. The paper proposes a methodology based on the integration of two existing approaches and finalized to support designers, constructors, developers, and public authorities in the decision-making process. The first approach is based on a joint application of Life Cycle Assessment (LCA) and Life Cycle Costing (LCC). The outputs are proposed as an input to the second approach, the Strategic Choice Approach (SCA), considered as a preliminary “platform” in which information deriving from three specific disciplines (“Materials Science and Technology”, “Environmental Technology” and “Real Estate Market Evaluation”) could be structured, shared and accessed by stakeholders, in order to facilitate the decision-making process. First findings are illustrated through an application of the proposed methodology on a case study in the city of Turin (Northern Italy). The selected case study constitutes a reference building for the Turin area because it represents the building construction techniques that mostly need to be refurbished in order to reduce energy consumptions at building level and, as a consequence, at urban level.     

Automated performance measurement for 3D building modeling decisions

Building information modeling (BIM) is instrumental in documenting design, enhancing customer experience, and improving product functionality in capital projects. However, high-quality building models do not happen by accident, but rather because of a managed process that involves several participants from different disciplines and backgrounds. Throughout this process, the different priorities of design modelers often result in conflicts that can negatively impact project outcomes. To prevent such unwanted outcomes from occurring, the modeling process needs to be effectively managed. This effective management requires an ability to closely monitor the modeling process and correctly measure the modelers' performance. Nevertheless, existing methods of performance monitoring in building design practices lack an objective measurement system to quantify modeling progress. The widespread utilization of BIM tools presents a unique opportunity to retrieve granular design process data and conduct accurate performance measurements. This research improves upon previous efforts by presenting a novel application programming interface (API)-enabled approach to (a) automatically collect detailed model development data directly from BIM software packages in real-time, and (b) efficiently calculate several modeling performance measures during schematic and design development phases of building projects. These indicators can be used to properly arrange modeling teams in the quest for high-quality building models. The specific objectives of this study to examine the feasibility of a proposed automated design performance measurement framework, and to identify optimal modeling team configurations using empirical performance information. A passive data recording approach allows for the real-time capture of comprehensive user interface (UI) interaction and model element modification events. The proposed framework is implemented as an Autodesk Revit plugin. Next, an experiment is conducted to capture data using the developed Revit plugin. Experiment participants' individual production rates are estimated to establish the validity of the proposed approach to identify the optimal design team configuration. The presented approach uses the earliest due date (EDD) sequencing rule in combination with the critical path method (CPM) to calculate the maximum lateness for different design team arrangements.     

Ancient vernacular architecture: characteristics categorization and energy performance evaluation

Building has significant impacts on the environment and natural resources. The emerging world energy and environment challenges demand a substantial revolution of building design philosophies, strategies, technologies, and construction methods. Vernacular architectures, built by people whose design decisions are influenced by traditions in their culture, have been gleaned through a long period of trial and error and the ingenuity of local builders who possess specific knowledge about their place on the planet, and thus are valuable in promoting climate-specific passive building technologies to modern buildings. This study introduced an approach to categorizing distinct vernacular regions and evaluating energy performance of ancient vernacular homes as well as identifying optimal constructions using vernacular building techniques. The research conducted an extensive computer energy modeling for a number of representative ancient vernacular architectural characteristics observed for different climatic regions. The vernacular test subjects were compared against those established according to the International Energy Conservation Code and those generated by the optimization software. The simulation results of the energy models suggest that considering traditions seen in ancient vernacular architecture as an approach to improving building energy performance is a worthwhile endeavor and a scientific guidance can help enhance the performance. The study indicates that, although many vernacular dwells exist in the world, it is challenging (but desired) to package vernacular architecture traditions and quantitative design knowledge to modern building designers. This project is the first part of a much larger project that intends to create a knowledge base of vernacular building traditions that will include information about not only the energy performance of traditional building techniques, but also address areas of cost, material availability and cultural traditions.     

Logic for ensuring the data exchange integrity of building information models

Industry domains require distinct data and structures of building information models developed and tailored for their disciplines. To seamlessly exchange the building information models, Industry Foundation Classes (IFC), which is one of neutral formats, has been broadly used the architecture, engineering and construction, and facility management industries. Model views definitions (MVD), which is one of the IFC sub-schemas used by domain experts and BIM software vendors, consists of IFC-mapped data exchange requirements of each domain and helps software vendors develop IFC import and export features that allow project participants share and exchange BIM information. Because of the heterogeneous translation processes and structures of IFC interfaces according to model views, their validation is imperative to ensure the integrity of BIM data and maintain a consistent data exchange environment. To accomplish this objective, this paper suggests a new approach to evaluating BIM data in accordance with diverse requirements of MVD. Since MVD entails various types of data exchange specifications, this research examines their embedded checking rule types and categorizes corresponding implementation scenarios. In addition, this paper involves rule logic and IfcDoc-based BIM data validation developed based on the logical rule compositions of identified rules types and checking scenarios. This approach is expected to support sharing consistent BIM data sets and confirming the quality of received data pertaining to the syntax and semantics of a targeted model view.     

Managing complex project process models with a process architecture framework

Especially in large, complex projects, various aspects of process (activity network) information reside in separate models and diagrams that can become unsynchronized over time. Prior research has introduced the concept of a process architecture framework (PAF), which provides a solution by tying all the models and diagrams together in a single, rich process model with many views, where each view presents a subset of model information. This paper advances that work by (1) proposing an expandable PAF structure that organizes 27 + new and existing views, (2) suggesting examples of three new views that align well with specific concerns of users, and (3) presenting insights to guide the development of new views. Thus, this paper takes further steps towards the development of a PAF that provides at once both simplicity and completeness for project managers and other users of process models and project management information systems.     

Assessing scalability of a low-voltage distribution grid co-simulation through functional mock-up interface

State-of-the-art Modelica tools for modelling and simulating multi-physical systems have reached certain maturity among the building physics community. Hence, simulation is widely used for control, sizing and performance assessment of energy systems. However, serious efficiency issues arise for large-scale models. This article proposes a practical application of co-simulation methods on detailed district energy systems. The aim of this study is to assess performance and scalability of co-simulation through functional mock-up interfaces on a detailed and multi-physical district model. In particular, we propose a comparative analysis between classical simulation and co-simulation methods and a scalability analysis on a growing number of buildings. The models have been implemented using Modelica language and the OpenIDEAS library. A decomposition approach is taken for modelling the entire system, while stochasticity in the inputs is taken into account. Results are presented for various integration scenarios, including a classical integrated simulation for reference and co-simulations involving different master-algorithms within Dymola and DACCOSIM 2017. Scenarios are compared in terms of speed-up and accuracy of principal physical quantities representing key performance indicators such as indoor temperature, current and voltage at building's connection. The analysis shows that co-simulation can run up to 90 times faster than the integrated simulation for 24 buildings, while ensuring acceptable accuracy.     

Transformation of a 4D product and process model to generate motion of mobile cranes

Modeling and visualization of motion of mobile cranes enable project engineers to identify possible spatial conflicts related to cranes prior to actual operation on job sites and hence, could minimize hazardous conditions and delays associated with spatial conflicts. Current tools for visualizing equipment motion in three dimensions (3D) and across time have limitations due to their reliance on users in modeling a sequence of movement of each piece of equipment experientially and manually. This paper presents an approach for automatically generating motions of mobile cranes to support conflict detection. This approach builds on and extends existing approaches in product and process modeling and visualization of construction operations. It takes a product and process model that contains building design and schedule information of a specific project together with specifications of cranes and construction methods utilized by the project as input. The crane specifications and construction methods constitute project-independent information that describes how cranes should be operated during the execution of activities. The output of the approach is a transformed product and process model that incorporates a set of operations and motions of cranes, which can be used for identifying spatial conflicts associated with crane operations. Validation studies show that the developed approach can be used to model different types of mobile cranes and generate their motion during operations, which enables detection of spatial conflicts related to cranes.     

The choice of optimal checking strategies for error control in structural engineering

Probabilistic models are given for estimatingthe error content in a structure afte.r thre" application of a checking strategy with given efficiency. The use of these models to optimize the level of effort expended on error control is illustrated. The analysis is carried out using-a Bayesian-decisiorv-theory approach,-and an overall model for structural decision-making is described. The applicability of the approach is illustrated by an example which considers the overall checking efficiency in the building process, combined with some failure statistics and failure cost estimates. The application of the approach to specific structural members is also discussed in the paper.     

基于演化博弈的工程总承包模式推广分析

推广工程总承包模式既符合工程项目组织实施方式改革的要求,也是国内建筑行业转型升级的迫切需要。在分析工程总承包模式推广所面临的国内和国际市场机遇与当前实施困境的基础上,运用制度变迁理论阐明了工程总承包市场的转变途径,即由强制性变迁向诱致性变迁的轨迹演变。通过构建“政府—业主”演化博弈模型,得出稳态平衡策略为政府激励业主,业主为追求最大利润而进行模式推广,从而扩大市场需求,实现市场诱致性变迁过渡。并提出了增加财政金融激励、完善市场制度环境、提升国际交流力度、构建完善信息平台等对策建议。     

Manipulating the flow of design information to improve the programming of building design

The increasing complexity of modern buildings and the use of fast-track methods of procurement systems has meant the expeditious and successful completion of the design phase of a project has become ever more important. This paper describes a research methodology that can help plan the building design process. Design models, based on data flow diagrams, have been developed to map information flows during the design of a modern building. These models are analysed using Steward's design structure matrix, which allows ordering of the tasks to produce schedules or design plans based solely on information flowing between design tasks. Traditional ordering is based on experience but modern complex projects require a more rigorous approach. Design is an inherently iterative activity and design structure matrix analysis reveals how to order most efficiently interdependent tasks and use estimates of design information further to improve the scheduling of design tasks.