Principles of Good Product Development

Simulation and rapid prototyping

In the coming years, there will be a lot of pressure on companies to improve their product development performance. They will have to develop products faster, at a lower cost, and with better quality. Simulation and rapid prototyping will help them meet these objectives.

Simulation is carried out to study the performance of a system, product or process before it has been physically built or implemented. It involves the development and testing of a computer-based model of a part or product.

Rapid prototyping is the production of a physical prototype directly from a computer-based model of a part or product.

Simulation has been used for many decades. It involves the development of a computer-based model of a part or product, the development of a computer-based model of the environment in which the part or product will be used, the testing of the part under different conditions of the environment, analysis of the behavior of the part, and modification of the model of the part to improve its behavior. The models of the part and the environment may be built graphically using a CAD system or they may be input in the form of equations. Computer-based simulation is cheap and effective. It makes it easier to evaluate before implementing. It allows errors to be identified and corrected before they are implemented. Models can be built, tested and compared for different concepts. 'What-if' analysis can be carried out. Recommendations for improvement can be made.

Simulation helps meets the objective of developing products faster because it does not require the time-consuming activities of building physical models of the part and the environment. Instead it uses the models designed in the computer which would normally be the basis for building the physical models. Time is saved because it is not necessary to build the 'physical' model. In addition, even more time is saved as modifications are made to the computer-based model and the simulation is repeated. Simulation is cheaper than the traditional methods of building and testing a physical model. There are savings in reduced material costs. There are savings because all the activities of defining the process for making the prototype and then building it and testing it are no longer needed. Quality is improved because it is possible to define and test many more potential designs using a computer-based model of the part than when using physical prototypes.

Rapid prototyping is used to produce an accurate 3D model directly from a CAD model. There are several rapid prototyping technologies such as stereolithography, instant slice curing, and selective laser sintering. Whereas one of the benefits of simulation is that a physical prototype is not needed, for some products there are nevertheless benefits of having a physical prototype. A physical prototype is a good visualization and communication tool for people unaccustomed, unable, or unwilling to work with an image on the screen. It provides a common language for people from different functions and eliminates misunderstanding. The parts produced can be used as fit and function models. They can be used as design verification tools, and patterns for other manufacturing processes. They can be used to check interference, and to test ease of assembly and maintenance.

The benefits of simulation come from use of computer-based models. The benefits of rapid prototyping come from use of physical models produced directly from computer-based models.

The activity prior to rapid prototyping is the development of a computer-based model of a part or product. This is the normal CAD design activity. It has to be carried out whether a prototype is going to be produced by rapid prototyping or traditional means. Once the CAD model exists, a physical model can be produced directly by one of the rapid prototyping technologies, whereas with traditional means, drawings of the CAD model would be produced, manufacturing engineers would decide how to produce it, and then it would be manufactured. Rapid prototyping cuts out these steps - so it saves the time associated with them, it saves their cost and it eliminates the possibility of transcription errors and misinterpretation.

Companies that don't use simulation and rapid prototyping will find their product development cycles are longer, and their development costs higher, than those of companies that do use them. Companies that don't have rapid prototyping and simulation should investigate how they would benefit from their use. Both practices offer the advantages of reducing development costs and cycles and improving quality. Some costs are involved in acquiring simulation and rapid prototyping systems, and in training people to use them. The balance between costs and benefits will change from one company to another, so each company has to look at its particular requirements in detail.

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Page last modified on March 10, 2000
Copyright 2000 by John Stark