Chapter 1 Geometric Dimensioning and Tolerancing Essentials 27 Copyright Goodheart-Willcox Co., Inc. There are a number of factors that companies consider when deciding on which CADD software and documentation format to use in design. Primary considerations include the following: • Processes and practices used in design and drafting • Industry standards • Project requirements • Project collaboration needs • Software costs • Training costs • Management and maintenance costs • Software provider user support Multiview drawings created in 2D format are the standard documentation format in manufacturing. This format is used in projects where design is not complex, exten- sive revision is not common, and advanced analysis tools are not needed. Solid mod- eling is a more effective solution in more complex projects. Designs created as solid models allow for the use of advanced visualization, simulation, and analysis tools. Advanced solid modeling software is more expensive than 2D drafting software, but the investment can prove cost efficient when more projects make use of special design and analysis tools. Often, projects require a combination of CADD design formats and software. The ability of an organization to use different CADD design formats and software presents numerous advantages and optimizes flexibility. Applying GD&T with CADD CADD has revolutionized all aspects of design and drafting, including methods of applying GD&T. CADD allows you to quickly and accurately place and edit GD&T symbols. To add GD&T content to a CADD drawing or model, study the CADD sys- tem you intend to use for proper technique, and refer to this textbook for correct size, format, and use of ASME Y14.5-2018 symbols. Applying GD&T to a drawing or model varies depending on the CADD software, the tools and options used to generate symbols, and the purpose of the symbols. You may have to select points or objects, choose values, or build symbols from scratch. Basic CADD programs require the user to build symbols using line, shape, and text tools. More powerful CADD software, such as Autodesk AutoCAD, includes specific commands for adding some GD&T symbols. Mechanical design and drafting CADD software systems such as Autodesk Inven- tor, Autodesk Fusion 360, Dassault Systèmes SolidWorks, PTC Creo, Siemens NX, and Siemens Solid Edge offer more comprehensive GD&T tools and symbols. These programs and other software programs designed for manufacturing applications are sometimes called mechanical computer-aided design (MCAD) software. Some MCAD software provides tools intended to help users add GD&T to designs. Third-party add-ins with more GD&T symbols are also available for some programs. Applying GD&T on Engineering Drawings An engineering drawing is a representation that shows the size and shape of all features and the dimensions necessary to define product requirements. Designers using CADD prepare 2D drawings by creating part geometry or by extracting drawing views from 3D model data. Refer to the drawing of the hub in Example 1-22A. Features typically appear on a drawing in a “basic,” or theoretically perfect, state, with size and loca- tion parameters stored in a database. The designer adds dimensional information and