بهبود بهره وری از طریق اجرای همزمان وظایف بولین

Computer-Aided Design (CAD) applications provide design and engineering professionals with various computer-based tools to perform design activities. As efficiency is one of the most important requirements in most design tasks, in this article, we contribute a novel collaborative design approach to improving efficiency, where a complex design task can be divided and executed concurrently by multiple collaborative designers. This approach is particularly effective for design tasks where Boolean operations – widely supported by most CAD applications – are heavily used in design activities, such as architecture design, mechanical design and digital media design. We have designed and implemented a prototype system CoAutoCAD to test the approach and to demonstrate a variety of collaborative design activities.

Computer-Aided Design (CAD) applications provide design and engineering professionals with various computer-based tools to perform design activities. A CAD application can be used to design, develop and optimize products, which can be goods used by end consumers or intermediate goods used by other products. It is also extensively used in domains such as machinery design, manufacturing and urban planning, from small residential types (e.g., houses) to large commercial and industrial structures (e.g., hospitals and factories). Ever since introduced to its applicable fields, CAD applications have constantly been improved to meet specific requirements such as lowering product development costs, shortening design cycles and consolidating valuable ideas from various sources. According to Gero (2000), design activities can mainly be classified into two kinds: routine designing and nonroutine designing. Routine designing produces designs that are some minor variations of existing ones, which means that most of the design tasks and details are known even before a design process starts. Efficiency is an important requirement in most routine design tasks and various approaches have been developed to help improve design efficiency. One of the approaches is “collaborative design” or “collaborative engineering” (Shen, Hao, & Li, 2008), which allows designers from multidisciplinary domains and geographically dispersed locations to work on a common project. The approach is able to help coordinate routine design activities and share design information in a complex design project that involves multiple designers by employing advanced collaboration technologies, e.g., video conferencing (Egido, 1988) and application sharing (Begole, Rosson, & Shaffer, 1999). In the past decade, we have witnessed the invention of lots of applications and tools in the fields of engineering, CAD and CSCWD to support routine designing. Those applications and tools are able to construct effective communication channels between distributed designers. They are also equipped with methods and techniques to support design planning (Li et al., 2010 and Yu and Li, 2006), which can divide a big design project into smaller design tasks, assign them to individual design teams/experts, and coordinate the integration process of the tasks. While those methods and techniques are effective in improving design efficiency at a higher level (i.e., project level), not much work has been done to support improving efficiency at the lower level (i.e., task level). As today’s design projects are usually huge and interdisciplinary, a design task divided from a project could still be complex enough for a designer to perform. As a result, the process of completing individual tasks is usually tedious and error-prone, and easily among one of the root causes that lead to design inefficiency. To tackle this problem, in this article we propose a collaborative design approach to improve efficiency in routine design by further dividing a task into subtasks and allowing multiple designers to complete the subtasks in parallel. In practice, it is non-trivial to decompose a complex design task and integrate the subtasks. An expert system with collaborative functionalities must exist to help designers complete this process. Such a system should have the following features: (1) Division and integration. A complex design task usually needs to be performed by multiple designers who have different specialties, habits and culture backgrounds. They can contribute to a design task from different perspectives. There are usually three steps in the process (which can be done in sequence or in parallel): dividing a task to multiple subtasks, allowing individual designers to perform the subtasks, and integrating the subtasks. While designers can use the functionalities provided by the design tools to perform the subtasks, the system should provide flexible mechanisms to help integrate the subtasks. (2) Tools and design environments. Designers’ proficiency in using a design tool is a key factor to determine the efficiency of completing a design task. A new tool should retain the “look-and-feel” and functionalities of the tools that designers are familiar with. Otherwise, design efficiency could be compromised by the learning curve. (3) Visualization and review. In a collaborative design environment, a designer needs to be informed of others’ work in order to avoid potential conflicts. This implies that the collaborative design tool should enable visualization of individual designers’ work in the shared workspace in real time. Therefore, we have designed and implemented a collaborative design tool CoAutoCAD (Zheng, Shen, & Sun, 2009), which integrates advanced collaborative functionalities into one of the most widely-used commercial-off-the-shelf design tool AutoCAD (Autodesk, 2010). CoAutoCAD retains AutoCAD’s “look-and-feel” and conventional single-user features, but is equipped with advanced collaborative functionalities such as concurrent work, conflict resolution, and consistency maintenance. In this article, we present a novel solution to improving efficiency in routine design, where a complex design task can be divided and executed in parallel by multiple collaborative designers. This solution is particularly effective for design tasks where Boolean operations – widely supported by most CAD applications – are heavily used in design activities, such as architecture design, mechanical design and digital media design. This solution has been implemented in CoAutoCAD for testing its effectiveness and demonstrating a variety of collaborative design activities where design efficiency can be significantly improved. The rest of this article is organized as follows. In Section 2, we briefly review the design of the CoAutoCAD system. The technical background of tackling the negative side of conflicting operations in CAD applications is introduced in Section 3. Section 4 describes how to improve design efficiency by concurrent execution of Boolean tasks using CoAutoCAD. Finally, major contributions of this article and the future work are summarized in Section 5.

CAD applications provide design and engineering professionals with various computer-based tools to perform design activities. As efficiency is one of the most important requirements in most design tasks, in this article, we contribute a novel collaborative design approach to improving efficiency, where a complex design task can be subdivided and executed concurrently by multiple collaborative designers. This approach is particularly effective for design tasks where Boolean operations – widely supported by most CAD applications – are heavily used in design activities, such as architecture design, mechanical design and digital media design. We have designed and implemented a prototype system CoAutoCAD to test the approach and to demonstrate a variety of collaborative design activities. With the presented technique, a BT can automatically be divided into subtasks, which are easy for designers to understand and to execute. It should be pointed out that, although the presented technique supports collaboration of multiple designers, it does not necessarily require that the work be done by multiple designers. In fact, software agents can also be employed to make the concurrent execution process automatic. For example, to concurrently execute a subdivided task, a designer can start several agents, which then work in a collaborative design mode. The designer just needs to assign subtasks to these agents. The designer can even just input the expressions of a BT, do some configurations (e.g., the number of employed agents) and leave all the real work to the software agents. It should be pointed out that the presented technique does not necessarily lead to design efficiency improvement in a design activity, because the improvement is also dependent on other factors, especially designers’ qualities such as visions, experiences, instincts and attitudes. Practically, major reasons due to which a designer may not be able to complete a task include technical reasons such as a tight working schedule, incompetent design skills and poor project management skills, and social reasons such as being not collaborative and having different opinions. As the presented technique can significantly reduce the complexity of a complex design task, it increases the possibility for the technical problems to be resolved (or at least reduced). While solutions (Santoro et al., 2006 and Lu et al., 2000) to the social problems are beyond the scope of this article, we believe that the technical and social solutions can be integrated to achieve an even more significant increase in design efficiency. The technique introduced in this article is currently applied to design work involving Boolean operations. The cornerstone of the technique is the thorough understanding on the relationship between multiple concurrently executed Boolean operations. In the future, we will extend the technique to improve design efficiency by concurrent execution of other geometry-based CAD operations such as trim, extend and rotate.