Digital mockup (DMU) is the digital description of a product, usually in 3D, for its entire life cycle. Digital mockup is enriched by all the activities that contribute to describing the product. The product design engineers, the manufacturing engineers, and the support engineers work together to create and manage the DMU. One of the objectives is to have important knowledge of the future or the supported product to replace any physical prototypes with virtual ones, using 3D computer graphics techniques. As an extension it is also frequently referred to as Digital Prototyping or Virtual Prototyping. These two specific definitions refer to the production of a physical prototype, but they are part of the DMU concept. DMU allows engineers to design and configure complex products and validate their designs without ever needing to build a physical model.

Mockups helps to visualise how all design decisions play together, they are convincing and closely resemble the final product, it can be easily revised rather than much later in production stage, It also helps in visualisation of package design projects in 3D & speed up approvals.

Among the techniques and technologies which make this possible are:

• the use of light-weight 3D models with multiple levels of detail using lightweight data structures such as JT XVL and PDF allow engineers to visualize, analyze, and interact with large amounts of product data in real-time on standard desktop computers.
• direct interface to between Digital Mockups and PDM systems.
• active digital mockup technology that unites the ability to visualize the assembly mockup with the ability to measure, analyze, simulate, design and redesign.