1. Introduction

Architecture, Engineering and Construction (AEC) industry deals with many activities such as planning, estimation, structural analysis, design, detailing and drafting, construction planning and scheduling, materials procurement and management, fabrication, erection, quality control, cost control and management of human, material, equipment  and financial resources concerning any construction project. These activities   involve large-scale use, generation, and exchange/sharing   of textual and graphical data/information (in the form of engineering drawings and documents) among owners, architects, design engineers, builders, contractors, suppliers, financiers, and managers. Computer programs/software are being used extensively to find optimal solutions for different problems in design and construction and to create necessary data/information for the actual construction process. The project data/information needs to be exchanged/shared efficiently among the parties concerned to improve productivity.  The term information used here implies/includes also the interpretation by human beings.  Presently, data/information exchange is mostly in the form of documents/reports (containing design data, schedules, etc.) and engineering drawings, either by paper-based or e-mail communication.  It needs significant human interaction to interpret and transfer data/information from one party/application to the other involving   considerable delays and possible errors. Therefore, vigorous efforts are being made worldwide to develop models for creating an integrated environment for computer applications and information exchange in the AEC industry. The importance of such efforts can be seen from the findings in the report [ 1 ], based on a study sponsored by National Institute of Standards (NIST), which estimates the cost of inadequate interoperability in the U.S. capital facilities industry to be $15.8 billion per year. This emphasizes the need for development of appropriate and efficient information modeling, storage and exchange methods, which may be termed as   Architecture, Engineering, and Construction Informatics (AECI). This paper presents a brief overview of the historical background of developments in computer applications, present scenario, and future directions for the development of AEC informatics. Information modeling principles and object-oriented approach for development of AEC Informatics have been briefly dealt with in the paper keeping in mind the integration of all computer applications of the AEC industry. The scope of the paper has been limited to the technical aspects of design and construction, with the possibility to integrate with business process applications as well.

2.  Nature of AEC Information

Information concerning any construction project grows rapidly and undergoes changes from the initial phase of conceptual planning to the phase of its completion. The information about the constructed structure/facility also undergoes continuous change during its maintenance and the total life cycle.  Information may consist of data about many aspects such as physical form, topology, location,  ownership, appearance and the constituent materials besides the behavioral aspects such as the strength, serviceability and performance of the building/structure and the concerning methods/decisions.  Different items of information are inter-related.  At the initial stages of any project, generally the architect generates a conceptual plan, keeping in mind the functional requirements, in the form of sketches/drawings and documents describing various features/aspects and preliminary estimates.  This textual and graphical data forms the input for preliminary analysis and design, which produce more detailed data and other information.  Decisions are made at every phase to freeze the information which forms the basis for the next phase.  Detailed calculations and expert judgments are involved in finalizing several aspects of detailed design, and construction planning and scheduling.  The transfer/exchange of  information from one phase of activity to the next is traditionally done sequentially, which is time consuming, on the other hand, the present trend is to devise ways to carry out activities concurrently in different phases, which leads to fast track execution of execution of projects. This requires an efficient way of exchange of information.

Application of Information and Communication  Technologies (ICT) in the construction industry poses more challenges [2]  than its use in the traditional manufacturing industries such as the automobile industry due to the fact that (i) construction involves one-of-a-kind products such as buildings and bridges that are usually unique, (ii) Construction products are designed, built and maintained as a one-of-a-kind process, (iii) each  process is carried out by a one-of-a-kind team of investors, contractors and subcontractors, and (iv) team members vary in size, budget and level of IT expertise and are typically small to medium enterprise.