Databases and Applications Programs
The usefulness of a database organization is particularly evident in integrated design or management environments. In these systems, numerous applications programs share a common store of information. Data is drawn from the central database as needed by individual programs. Information requests are typically performed by including pre- defined function calls to the database management system within an application program. Results from one program are stored in the database and can be used by subsequent programs without specialized translation routines. Additionally, a user interface usually exists by which a project manager can directly make queries to the database. Figure
5-6 illustrates the role of an integrated database in this regard as the central data store.
An architectural system for design can provide an example of an integrated system. First, a database can serve the role of storing a library of information on standard architectural features and component properties. These standard components can be called from the database library and introduced into a new design. The database can also store the description of a new design, such as the number, type and location of individual building components. The design itself can be composed using an interactive graphics program. This program would have the capability to store a new or modified design in the database. A graphics program typically has the capability to compose numerous, two or three dimensional views of a design, to introduce shading (to represent shadows and provide greater realism to a perspective), and to allow editing (including moving, replicating, or sizing individual components). Once a design is completed and its description stored in a database, numerous analysis programs can be applied, such as:
z structural analysis,
z daylight contour programs to produce plots of available daylight in each room, z a heat loss computation program
z area, volume and materials quantities calculations.
Production information can also be obtained from the integrated system, such as:
z dimensioned plans, sections and elevations, z component specifications,
z construction detail specifications, z electrical layout,
z system isometric drawings,
z bills of quantities and materials.
The advantage of an integrated system of this sort is that each program need only be designed to communicate with a single database. Accomplishing appropriate transformations of data between each pair of programs would be much more difficult. Moreover, as new applications are required, they can be added into an integrated system without extensive modifications to existing programs. For example, a library of specifications language or a program for joint design might be included in the design system described above. Similarly, a construction planning and cost estimating system might also be added.
The use of integrated systems with open access to a database is not common for construction activities at the current time. Typically, commercial systems have a closed architecture with simple datafiles or a "captive," inaccessible database management system. However, the benefits of an open architecture with an accessible database are considerable as new programs and requirements become available over time.
Example 5-2: An Integrated System Design
As an example, Figure 14-7 illustrates the computer aided engineering (CAE) system envisioned for the knowledge and information-intensive construction industry of the future. In this system, comprehensive engineering and "business" databases support different functions throughout the life time of a project. The construction phase itself includes overlapping design and construction functions. During this construction phase, computer aided design (CAD) and computer aided manufacturing (CAM) aids are available to the project manager. Databases recording the "as-built" geometry and specifications of a facility as well as the subsequent history can be particularly useful during the use and maintenance life cycle phase of the facility. As changes or repairs are needed, plans for the
facility can be accessed from the database.