The Release-to-CAD Revolution
When are critical engineering decisions made in your engineering process? Do last-minute design changes delay release-to-manufacturing or product delivery? How can you be certain that your products address customer requirements while maximizing profitability?
Traditionally, the release-to-manufacturing milestone served as the critical event when design decisions were finalized. The CAD models and drawings themselves functioned as the ultimate engineering deliverable. This approach made sense: the product definition in CAD was typically the first opportunity for all engineering stakeholders to see how their ideas converged and to validate the product definition. Unfortunately, this process introduced significant waste: the CAD team inevitably invested considerable time detailing the designs before basic engineering concepts were proven. Every design modification required changes to the detailed designs, creating long iterations loops, design compromises, and delaying time-to-market.
As engineers are evaluating their design processes and identifying new ways to foster inno-
vation, reduce development time, and deliver more value to their customers, they’re discovering that emerging tools can empower more engineers to collaborate on concept models in the early phases of the design process, address cross-functional challenges and provide proven specifications to the detail designers using traditional CAD. The advent of direct modeling, a new approach to 3D design, is making 3D solid modeling accessible to all engineers, bringing 3D to a wider audience, beyond dedicated CAD users. Engineers are now able to work with customers and suppliers in real-time, use simulation and prototyping to prove concepts in advance of CAD, and eliminate risk and knowledge gaps before committing to the detailed designs that lock in the majority of product lifecycle costs. This fundamental improvement in the design process, referred to as “Release-to-CAD,” is revolutionizing the way products come to market. Engineering organizations deploying this process are reporting more than twofold improvements in time-to-market.
How do engineers achieve such impressive gains? The leaders create a clear separation between engineering models and design documentation: releasing the engineering data to CAD teams to perform design-for-manufacturing. Although concept engineers use 3D tools early in the design process, they spend no more effort on these models than is necessary to iterate as quickly as possible, validating ideas with all possible stakeholders, including all engineering teams, customers, suppliers, manufacturing, and, of course, the detailed design team. They use these concepts to test all possible fitness functions on each concept, using simulation, prototyping, visualization, and costing tools to validate and optimize factors such as price, weight, materials, functionality, manufacturability, aesthetics, and market appeal—all before ever committing to detailed designs in traditional CAD systems.
The leading companies that engage in release-to-CAD do not typically use the same CAD systems for concept work and detailed design. The engineering process of concept modeling motivates substantially different requirements from the process of detailed design. When engineering a product, the main activity is exploring iterations that impact a product’s form, fit and function and gaining enough understanding of the trade-offs in these options to make critical design decisions. This activity requires a tool that is fast and flexible, and that does not constrain an engineer from making innovative leaps. When documenting a product, however, the goal is to unambiguously define the product, and provide a precise definition to manufacturers and suppliers so that they can produce the finished product. Detailed design requires CAD tools that can lock down models and document the precise manufacturing specifications.
Most traditional CAD tools—those using the feature- or history-based modeling paradigm—are best-suited for detailed design. For example, in most traditional CAD systems, solid parts and sheet metal parts require different file types. If an engineer were to realize that a plastic part could be fabricated out of sheet metal, the designer would have to create a new part from scratch and delete the old one. During the concept phase, engineers require a tool without these limitations.
Direct modeling technology is emerging as the clear leader in concept design because it provides much greater flexibility to make these types of changes. Not only is it able to make radical changes without the foresight to build such design intent of the CAD files, it can work with existing data from traditional CAD systems, making it easy to generate new concepts from existing designs. Simultaneously, direct modeling tools typically don’t force engineers to add the constraints that lock down detailed design intent the way that detailed designers require. Therefore, in most release-to-CAD processes, engineering firms are using direct modeling to build the engineering model and traditional history-based modeling to lock down the detailed designs after the concepts have been release to the CAD team. Table 1 summarizes the capabilities of direct modelers and history-based modelers and their strengths and weaknesses for different design activities.
CAE is another use case where direct modeling is more suitable for concept work than traditional history-based tools. In the past, simulation would only occur after detailed designs had been created. This presented a two-fold problem. CAE usually requires idealized geometry that lacks small features such as rounds, holes, text, and other irrelevant geometry created on the detailed design, so the CAE and CAD teams needed to create new simplified models to perform simulation. Secondly, CAE occurred after CAD, so remodeling was required after every iteration. Concept models, however, typically contain the appropriate granularity for CAE, and best-in-class direct modelers can parameterize geometry on-the-fly to optimize models as analysts see fit.
Perhaps the most striking feature of direct modeling is that its conceptual simplicity allows engineers who don’t regularly use CAD to finally use 3D to generate ideas, answer design questions, and communicate feedback to the CAD. This new generation of technology makes 3D modeling more accessible and intuitive than ever before, resulting in a sufficiently low cost of ownership to allow all engineers to work in 3D.
Although conventional wisdom has suggested that all 3D design should be performed in one CAD system, leading engineering organizations are deploying separate direct modeling tools to engineers to get the concepts right as early as possible in the design process. While this process does introduce some remodeling, the time saved by avoiding late design changes creates enormous efficiencies and expedites time-to-market. Once all engineering stakeholders agree that the concepts best match product requirements, engineering can hand off the design to the detailing team in the best format possible: a precise and accurate 3D model.
