Abstract
This chapter presents the implementation of a system that visualizes the construction process using 3D modeling data and schedule data to analyze construction planning. Previous papers have emphasized the benefits of visual 4D planning that combines 3D modeling data and process schedule data for work progress control. The proposed methodology offers rapid visualization of work performance with scheduled activity and facilitates construction planning and schedule inspection. Consequently, it should increase productivity and reduce rework. However, even major construction companies will not adopt such a work style, because the existing, well-organized way of working would not be readily changed unless the new style is proven to afford benefits that outweigh the effort and cost required to adapt to the style. The advanced CAD system, for example, is able to simulate the assembly process, and the advanced 3D graphic designer is able to animate the arrangement of objects. Even though each software provides multiple functionalities, the applications in practical use are all independent and specific, such as CAD for designing 3D models, and a project manager for scheduling and analyzing. Therefore, a system that integrates all outputs from each application is required to move from the conventional work style to the new one. This chapter, thus, aims to develop a system that integrates several types of data and enables the simulation of the construction progress by gradually showing 3D models according to the activity schedule. It is also possible to attach material data to each object and to display related information like cost and object properties. The system assumes the following requirements: (1) to import and display the 3D modeling data, (2) to import the project schedule, (3) to link each model and activity, (4) to give the material data on each object to enhance reality, and (5) to show cost accumulation. These functions are supposed to be realized such that the system utilizes the resources previously reserved. Therefore, the system should be able to import a DXF format file for 3D modeling data and access the MDB format database for the project schedule, including costs. The MDB file is originally a database that Microsoft Access creates. Microsoft Project, which is probably the most widely used software for project management, is also able to export the project data in this format. These functions are implemented with Microsoft Visual C++ and DirectX SDK. Although the system displays inaccurate models partially because of the misinterpretation of the DXF file, all of the demands listed above are satisfied currently. The authors of this chapter are now at the stage of implementation of further functions, that is, to display not only structures but also other elements such as the temporal space on the site, the route of delivery vehicles, and the work area of the temporally used heavy machinery, all for the sake of the visualization and analysis of the entire construction site.
Top1. Introduction
Previous papers have emphasized the advantages of architectural methodologies that use 4D data that associate three-dimensional modeling data with constructional timing. In recent times, the construction industry has aimed to rationalize the production system by deriving the benefits afforded by the integration of procedures ranging from designing to construction, and therefore, promoting the use of a 3D CAD system. The aim of recent 3D CAD technology is to provide a platform to unify several types of data that project members share, including data related to design, construction, and facilities; earlier CAD technology could only provide data related to the intended design at an early planning stage or a consistent drawing at the final planning stage. Technical issues at the construction stage are considered from the early design stage. Combining design with production in such a manner, called production design, allows the user to rapidly show the work progress and the completed amount of work as well as to reduce rework and redesign at the post-process stage since visualization at an early stage helps identify technical problems. Such a methodology requires various types of applications, including a CAD system, to design, plan, manufacture, and manage the process. However, it should be noted that the interchangeability of shared data between the software is not sufficiently high, and thus, the efficiency of the entire project is not improved considerably. The product model is being developed as a good solution for interoperation among different systems. Product model is a generalized data model that expresses three-dimensional shapes and information about the attributes of each element that composes a structure. The data set can be shared by various systems or applications when it is created as a product model, as shown in Figure 1.
Figure 1. Data sharing using product model
Despite the advantages of the abovementioned method, even major construction companies do not adopt such a work style. In fact, two-dimensional drawings are still widely used for design drawing and construction planning. Although a 2D drawing is sufficient for a designer, it is hardly possible for less-experienced people to visualize the 3D aspect from the 2D drawings, and besides, it is not suitable to simulate or analyze the problems on a PC. It appears that the conventional way of working will not change easily unless the new style can be clearly shown to afford benefits that outweigh the effort and cost required to adapt to this style.
Considerable cost is involved in deriving the benefits of the new methodology in order to, for example, produce a new set of data structures such as the product model, simulate the assembly process on an advanced CAD system in addition to designing, or animate the arrangement of objects on a high-performance 3D graphic designer. Even though each software provides multiple functionalities, the applications in practical use are all independent and specific, such as CAD for designing 3D models and a project manager for scheduling. Therefore, a system that integrates all outputs from each application is required to move from the conventional work style to the new one.
This study proposes a system that integrates data created by several applications, whereas other studies have suggested the integration of applications. The main part of this system is the visualization of process control using a 3D shape linking the schedule. Visualization in this case includes not only showing a construction state but also simulating the entire construction field by using heavy machinery and material carriers along with their route and the situation of temporary stores, in order to examine the entire construction plan in advance. Although all required data is created by different applications, the proposed system offers the functionality to link associated data from each dataset, and thus, it provides the same advantages as 4D CAD without the necessity of creating a product model or any other new type of data structure. Therefore, users can concentrate only on using the generic application specified for each purpose, such as CAD and Microsoft Project (MS-Project), in the usual manner.
This chapter describes the implementation of software that simulates the work progress by visualizing the given drawing data and linking them with schedule data.