CAD Software Blog


A Top-Down Design Interruption: Late Changes

Top-down design offers development teams an excellent platform for concurrent engineering. If you use PTC Creo Advanced Assembly Extension (AAX), you may already be using this method to create an assembly where several team members can work on the same product at once without fear of intruding on each other’s’ work, overwriting it, or having to wait for others before you can complete your design work.

With PTC Creo AAX, everyone in the team is aware of everyone’s design space, common outlines, interfaces, and design intent. But what happens when that initial geometry everyone depends on needs an unexpected change late in the design process? That’s when things can get messy.

Top-down assemblies with PTC Creo AAX

If you’re not familiar with PTC Creo AAX and how it enhances concurrent engineering, here’s how it typically works: You create a skeleton structure that sets aside space for each sub-assembly and provides a common interface and outlines that are shared across the team. Then individual designers can work on just their part of the assembly.  This provides significant benefits to a design team in terms of productivity and efficiency.

Imagine an assembly line. The skeleton model might include a gantry, and spaces for assembly stations, cabling, etc. Check out this video for a fuller explanation:

The trouble is, if a late-change is required to the top-down assembly, it will likely impact many models that reference those common interfaces, and subsequently any other related design intent. For example, the dimensions laid out for the gantry might need to be shortened to fit a new building. What will that mean to the stations and the cabling?

Today, if an engineer receives a top-down update, he or she can either apply the change, update to the new version, and deal with the consequences or ignore the change and work with an out-of-date assembly design. That’s not very helpful if you want to see the impact and make adjustments throughout the model to accommodate the top-down change. So, typically, engineers create a backup of the entire model to make sure work’s not lost as changes are made.

 

Design Exploration: A Better Workflow for Updates

With the new PTC Creo Design Exploration Extension (DEX), there’s a better way to understand and manage late changes to a model that’s been set up with a top-down structure.

When you combine PTC Creo DEX with PTC Creo AAX, you get Update Control.

Update control supports the engineer in four ways:

  • Provide notifications of a change to the reference model
  • Visualize what’s changed compared to the original
  • Manage how these changes are handled
  • See the impact of changes and explore alternative design proposals through DEX.

A DEX session will allow you to develop checkpoints so that you can experiment and understand the impact of the top-down change,—all without the manual efforts of creating a backup and without disrupting your workflow, and before you actually commit to it.  This ensures that redundant effort or re-work is greatly reduced.