There has been a lot of discussion about "Bottom Up" and "Top Down" modeling. 3DCS can support both strategies depending on the project. The project managers will determine what method you should follow. Here is a brief summary of the two techniques.

The "Bottom Up" or "Piece Part" modeling philosophy focuses on creating and verifying the Tolerances to the GD&T first. The Moves can be created next and verified to ensure that the model reflects the manufacturing process. The Measurements could then be created last and can be added anywhere in the validated model to determine if the Objective of the model was met.

The "Top Down" or "Black Box" modeling philosophy tends to focus on creating and checking the Measurements first and verifying the correct Objective Pt locations. The Model is based on sub-assembly locators and datums rather than piece parts. The Moves can be created next and verified to ensure that the model reflects the manufacturing process. Additional Moves may be created for alternate schemes (What-if's) to support robust concept selection. The Tolerances can be generic because the allocation process will determine the GD&T tolerance needed to meet the Objective.

The "Top Down" approach would involve creating 3-D models from x,y,z coordinates or from clay scans. Models can be generated from minimal math data to look at different strategies for process. When CAD data is complete it can be merged in with the original model. The model does not have to be regenerated when new data updates are available.

Models can also be generated by using concept model libraries for modeling common areas of the vehicle.

Bottom Up and Top Down Modeling

Bottom Up and Top Down Modeling

There has been a lot of discussion about "Bottom Up" and "Top Down" modeling. 3DCS can support both strategies depending on the project. The project managers will determine what method you should follow. Here is a brief summary of the two techniques.