Modern analysis and design processes in mechanical engineering are aided by various computational tools including finite element analysis (FEA), computational fluid dynamics (CFD), computer-aided design (CAD)/computer-aided manufacturing (CAM) and Failure Modes & Effect Analysis (FMEA). These modern processes facilitate engineers to model (create a 3D model or object in a computer), analyze the quality of design etc, before a prototype is created. By this the invention and experimenting with new designs becomes very easy and can be done without any money invested in tooling and prototypes. Simple models can be free and instantaneous, but complicated models, like those describing the mechanics of living tissue, can require years to develop, and the actual computation can be very processor intensive, requiring powerful computers and a lot of cycle time.

MCAD packages can be classified into three types: 2D drafting systems (e.g. AutoCAD, VectorWorks,MicroStation); mid-range 3D solid feature modelers (e.g. Inventor, TopSolid, SolidWorks, SolidEdge, Alibre Design, VariCAD); and high-end[7] 3D hybrid systems (e.g., CATIA, NX, Pro/ENGINEER).We here in San Diego , Silicon Valley and on the West Coast of the United States are familiar with these systems.

However these classifications cannot be applied too strictly as many 2D systems have 3D modules, the mid-range systems are increasing their surface functionality, and the high-end systems have developed their user interface in the direction of interactive Windows systems.

The capabilities of modern CAD systems include:

• Wireframe geometry creation
• 3D parametric feature based modelling, Solid modelling
• Freeform surface modelling
• Automated design of assemblies, which are collections of parts and/or other assemblies
• Create Engineering drawings from the solid models
• Reuse of design components
• Ease of modification of design of model and the production of multiple versions
• Automatic generation of standard components of the design
• Validation/verification of designs against specifications and design rules
• Simulation of designs without building a physical prototype
• Output of engineering documentation, such as manufacturing drawings, and Bills of Materials to reflect the BOM required to build the product
• Import/Export routines to exchange data with other software packages
• Output of design data directly to manufacturing facilities
• Output directly to a Rapid Prototyping or Rapid Manufacture Machine for industrial prototypes
• Maintain libraries of parts and assemblies
• Calculate mass properties of parts and assemblies
• Aid visualization with shading, rotating, hidden line removal, etc...
• Bi-directional parametric association (modification of any feature is reflected in all information relying on that feature; drawings, mass properties, assemblies, etc... and counter wise)
• Kinematics, interference and clearance checking of assemblies
• Sheet Metal
• Hose/Cable Routing
• Electrical Component Packaging
• Inclusion of programming code in a model to control and relate desired attributes of the model
• Programmable design studies and optimization
• Sophisticated visual analysis routines, for draft, curvature, curvature continuity.