Computer-aided Design (CAD) and Computer-aided Manufacturing (CAM) play an important role during the design and production phase of a product. CAD allows for generation of two and three-dimensional models of the product with the help of solid modelers and CAM allows for production planning of the product using tools such as a CAM package. Both CAD and CAM tools are highly specialized in nature and at the same time expensive to own. Large industries can afford to own such systems and experts to operate them but small and custom product industries cannot afford these benefits due to high design and manufacturing costs involved and complexity involved in using these systems. This has led to less popularity of CAD and CAM systems in custom product industries. A web based design tool can offer the functionality of a CAD system to custom product industries by allowing them to create and design three-dimensional models over the web. This method helps in simplifying the complexity involved in solid modeling by automating the commonly performed design operations using design algorithms. At the same time a web based manufacturing tool can allow for automatic generation of tool-paths for machining using a CNC machine. Although a web based design tool offers the required benefits to custom product industries, offering just the functionality of a CAD system may not be useful to the users of the web-based system who are usually carvers and artisans with minimal or no knowledge of CAD. An alternative method and its implementation are presented in this thesis. The method allows for creating user-defined parametric features using simple tools that can be offered in a web based application. The system takes advantage of the built-in API tools in a solid modeler and advanced web-based technologies to integrate them into a simple and easy to use web based design system. Identification of key elements in designing user-defined features and a framework for implementing them are discussed. Also different types of user-defined features that can be offered in a web application with examples of their implementation in a real world application for designing custom wooden signs are presented.

Computer-aided Design (CAD) and Computer-aided Manufacturing (CAM) play an important role during the design and production phase of a product. CAD allows for generation of two and three-dimensional models of the product with the help of solid modelers and CAM allows for production planning of the product using tools such as a CAM package. Both CAD and CAM tools are highly specialized in nature and at the same time expensive to own. Large industries can afford to own such systems and experts to operate them but small and custom product industries cannot afford these benefits due to high design and manufacturing costs involved and complexity involved in using these systems. This has led to less popularity of CAD and CAM systems in custom product industries. A web based design tool can offer the functionality of a CAD system to custom product industries by allowing them to create and design three-dimensional models over the web. This method helps in simplifying the complexity involved in solid modeling by automating the commonly performed design operations using design algorithms. At the same time a web based manufacturing tool can allow for automatic generation of tool-paths for machining using a CNC machine. Although a web based design tool offers the required benefits to custom product industries, offering just the functionality of a CAD system may not be useful to the users of the web-based system who are usually carvers and artisans with minimal or no knowledge of CAD. An alternative method and its implementation are presented in this thesis. The method allows for creating user-defined parametric features using simple tools that can be offered in a web based application. The system takes advantage of the built-in API tools in a solid modeler and advanced web-based technologies to integrate them into a simple and easy to use web based design system. Identification of key elements in designing user-defined features and a framework for implementing them are discussed. Also different types of user-defined features that can be offered in a web application with examples of their implementation in a real world application for designing custom wooden signs are presented.

Due to the multiplicity of computer-aided engineering applications present in industry today, interoperability between programs has become increasingly important. A survey conducted among top engineering companies found that 82% of respondents reported using 3 or more CAD formats during the design process. A 1999 study by the National Institute for Standards and Technology (NIST) estimated that inadequate interoperability between the OEM and its suppliers cost the US automotive industry over $1 billion per year, with the majority spent fixing data after translations. The Neutral Parametric Canonical Form (NPCF) prototype standard developed by the NSF Center for e-Design, BYU Site offers a solution to the translation problem by storing feature data in a CAD-neutral format to offer higher-fidelity parametric transfer between CAD systems. This research has focused on expanding the definitions of the NPCF to enforce data integrity and to support associativity between features to preserved design intent through the neutralization process. The NPCF data structure schema was defined to support associativity while maintaining data integrity. Neutral definitions of new features was added including multiple types of coordinate systems, planes and axes. Previously defined neutral features were expanded to support new functionality and the software architecture was redefined to support new CAD systems. Complex models have successfully been created and exchanged by multiple people in real-time to validated the approach of preserving associativity and support for a new CAD system, PTC Creo, was added.

The challenge of interoperability is to retain model integrity when different software applications exchange and interpret model data. Transferring CAD data between heterogeneous CAD systems is a challenge because of differences in feature representation. A study by the National Institute for Standards and Technology (NIST) performed in 1999 made a conservative estimate that inadequate interoperability in the automotive industry costs them $1 billion per year. One critical part of eliminating the high costs due to poor interoperability is a neutral format between heterogeneous CAD systems. An effective neutral CAD format should include a current-state data store, be associative, include the union of CAD features across an arbitrary number of CAD systems, maintain design history, maintain referential integrity, and support multi-user collaboration. This research has focused on extending an existing synchronous collaborative CAD software tool to allow for a neutral, current-state data store. This has been accomplished by creating a Neutral Parametric Canonical Form (NPCF) which defines the neutral data structure for many basic CAD features to enable translation between heterogeneous CAD systems. The initial architecture developed begins to define a new standard for storing CAD features neutrally. The NPCF's for many features have been implemented in a multi-user interoperability program and work between NX and CATIA CAD systems. The 2D point, 2D line, 2D arc, 2D circle, 2D spline, 3D point, extrude, and revolve NPCF's will be specifically defined. Complex models have successfully been modeled and exchanged in real time and have validated the NPCF approach. Multiple users can be in the same part at the same time in different CAD systems and create and update models in real time.

There are many different programs that can perform Computer Aided Design (CAD). In order for these programs to share data, file translations need to occur. These translations have typically been done by IGES and STEP files. With the work done at the BYU CAD Lab to create a multi-engineer synchronous heterogeneous CAD environment, these translation processes have become synchronous by using a server and a database to manage the data. However, this system stores part data in a database. The data in the database cannot be used in traditional Product Lifecycle Management systems. In order to remedy this, a new database was developed that enables every edit made in a CAD part across multiple CAD systems to be stored as well as worked on simultaneously. This allows users to access every action performed in a part. Branching was introduced to the database which allows users to work on multiple configurations of a part simultaneously and reduces file save sizes for different configurations by 98.6% compared to those created by traditional CAD systems.