Pro/ENGINEER Concurrent Design
Top Down Design & Large Assembly Management
1
Agenda
2

Top-Down Design Philosophy

Stages of Top Down Design

3D Design

Tip & Tricks

Question & Answer
Objectives
At the end of this tutorial, you will better understand how to:

Capture knowledge, or design intent, allowing you to concentrate
on significant issues by making the software perform tedious,
repetitive calculations.

Enable the framework for interchangeability of components
allowing for high-velocity product development by supporting
rapid iterations of product variations.

Create a concurrent design environment by spreading project
design responsibility across many organizational levels.
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Top-Down Design Philosophy
4
Traditional Design Approach
“Bottom-Up Design”
 Design
of individual components independent of the assembly
 Manual
approach to ensure that components fit properly and meet the design
criteria
 Components
and those placed in sub-assemblies are brought together to
develop the top-level assembly
 Errors
are manually identified and modifications to each component are made to
make the adjustment. As assembly grows, detecting these inconsistencies and
correcting them can consume a considerable amount of time
Top Level
Assembly
Component
Design
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Component
Design
Component
Design
Top-Down Design Philosophy
“Top-Down Design”
 Method
of placing critical information in a high-level location
 Communicating
that information to the lower levels of the product
structure
 Capturing
the overall design information in one centralized location
Design
Information
Component
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Component
Component
Why should you use it?
Benefits:
 Reduced design time
 Reduced errors (right the first time)
 Increased quality
 Better project management visibility
 Concurrent engineering
 Confidence in top-level regeneration
 Knowledge of how modules interface
 Top-level change control
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Example: to design an alternator...
What information should a designer need to work with most times?
Complete TopLevel Assembly
540 MB
Neighboring
Subassemblies
320MB
All Skeleton
Models in TopLevel Assembly
70 MB
Subassembly,
with Skeleton Model containing
all required information ~ 20 MB
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Stages of Top Down Design
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Stages of Top Down Design (TDD)
1.
Conceptual Engineering
Layouts and Engineering Notebook
2.
Preliminary Product Structure
Model Tree, PDM (i.e. Benevolent Dictator)
3.
Capturing Design Intent
Skeleton Models
4.
Manage Interdependencies
Reference Control & Viewer
5.
Communication of Design Intent
Copy & Publish Geometry
6.
Population of the Assembly
Constraints & Component Interfaces
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Stage 1
Conceptual Engineering Phase
Layouts and Engineering Notebook
Understand Existing Situation

High-level Requirements

Space Allocation
Define New Space and Motion

2D Sketches

3D Models

Rapid Iteration & Convergence

Animations
Capture Key Design Intent
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
Parameters

Notes

Relations / Calculations

Interfaces
Product Definition: Engineering Layout
What it is:

First thing done in design cycle

Used to evaluate key interface points

Used to evaluate key components of project
What it is Not:
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
Three dimensional solids

Fully detailed
Advantages of Using a Layout
 Document
design information in one centralized location
 Document
design information before creating solid models
 Investigate
 Easily
design options without involving the entire assembly
make design changes because all of the design
information is contained in one location
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Stage 2
Preliminary Product Structure Phase
Model Tree and PDM

Quickly define product hierarchy
•

Intuitive, automatic mapping to “start models”
•
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Before any of the components’ geometry is
defined
Templates ensure all designs share the necessary
common elements such as datums, layers, views,
parameters, etc.

Foundation for efficient task distribution

Component Creation Methods
•
Empty Components; Copy from start models
•
Automatic assembly of default datums
•
Unplaced & Partially-Constrained Components
#2 Product Definition: Assembly Structure
What it is:

Virtual Assembly / BOM

Used to organize assembly & assigning of design tasks

Used to input non-geometrical data up-front
What it is Not:
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
Three dimensional solids

Fully detailed

Fully constrained
Advantages of Defining Preliminary Product Structure

Defining the product structure prior to defining geometry can assist
you in organizing the assembly into manageable tasks that can be
assigned to design teams or individual designers.

Associate specific library parts (that are to be used on the project) with
the assembly at the start of the design, preventing confusion later.
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Advantages of Defining Preliminary Product Structure
Cont…

Submit the assembly to Pro/INTRALINK or PDMLink (or FIT dictator)
and assign models to the appropriate vaults or folders.

Individual designers can focus on specific design tasks instead of on
how their design is going to fit into the overall structure.

Input non-geometrical information such as the part number, designer’s
name, etc., at a very early stage.
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Stage 3
Capturing Design Intent Phase
Skeleton Models
What needs to happen?

Capture conceptual design parameters within
the context of the assembly

Capture & control critical object interfaces in
a single, convenient location
How? Skeleton Models…
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
Centralized pathway for communication

Facilitate task distribution

Promote well-organized design environments

Enable faster, more efficient propagation of
change

Special Treatment in BOMs, Simplified Reps,
Drawings, Model Tree & Mass Property
Calculations

Uniquely supported Scope Control Setting
#3 Product Definition: Skeletons
What it is:

Zero-mass geometry

Exact location detail

Minimized geometric detail
What it is Not:
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
Three dimensional solids

Fully detailed
Advantages of Using Skeletons
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
Provides a centralized location for design data

Simplifies assembly creation / visualization

Aids in assembling mechanisms

Minimizes unwanted parent-child relationships

Allows you to assemble components in any order

Controls propagation of external references
Stage 4
Manage Interdependencies Phase
Reference Viewer & Reference Graph
Tools to Manage References

External Reference Control
• Ensures
Top-Down Design
methodology is followed
• Incorporate
design management
rules directly into the design
• Ensures
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proper design reuse

Model Tree

Global Reference Viewer

Reference Graph
Reference Control
Benefits of Communicating Information From a Central Source

Task distribution

Concurrent modeling

Managing external references
Tools

Layout Declaration

Publish geometry

Copy geometry
The foundation is set … but topologically modifiable … it’s time for 3D.
With Reference Control Manager, you are safe to create your parts
directly in the assembly.
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Hierarchy
Top_level.asm

Top_level_skeleton.prt

Sub_assy_1.asm
Sub_assy_1_skeleton.prt

Sub_assy_2.asm
Sub_assy_2_skeleton.prt






Sub_assy_x.asm
Sub_assy_x_skeleton.prt
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3D DESIGN … FINALLY!
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Stage 5
Communication of Design Intent Phase
Publish Geoms, Copy Geoms
Publish Geometry Features

Provides ability to pre-determine the geometry to be referenced by
a Copy Geometry feature

Allows designers to define their interfaces to the rest of the design
Copy Geometry Features

Allows copying of all types of geometry

Surfaces, edges, curves, datums, quilts, copy/publish geometry

Retains copied geometry name and layer settings

Dependency on parent geometry can be toggled

Can be “Externalized”
External Copy Geometry

Build relationships on external models independent of an
assembly

Useful for coordinate system assembly practices
Simplified Representations, Display States & Shrinkwrap
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Stage 6
Population of the Assembly Phase
Automatic Component Constraints & Component Interfaces
What tools are available for
populating the assembly?


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Assembly Tools
•
Drag & Drop Placement
•
Component Interfaces
Component Creation
•
Within the context of the assembly
•
Mirror Parts or Subassemblies
Highlights of Top-Down Design
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
Capture knowledge, or design intent, allowing you to
concentrate on significant issues by making the software
perform tedious, repetitive calculations.

Enable the framework for interchangeability of components
allowing for high-velocity product development by supporting
rapid iterations of product variations.

Create a concurrent design environment by spreading project
design responsibility across many organizational levels.
Tip & Tricks
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Miscellaneous Tips
Separate Part Versus Assembly for Skeleton Features

Avoid constructing assembly-level skeleton features since the system
requires that you perform all edits of these features in Assembly mode.
• The
components can become an obstruction and degrade performance.
• Furthermore,
you cannot easily reuse skeleton features at the assembly
level in other subassemblies. By using a separate part file, you can edit the
feature in Part Mode and reassemble it into many different assemblies.
Geometry Features

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Place all static information in a skeleton as early as possible and place
all dynamic information later in the design process cycle.
Miscellaneous Tips
Datums for Skeleton Models

Consider renaming skeleton datums to “sk_”
Visualization

Use simplified reps and transparency prolifically to make viewing easier

Use “display states” to highlight different items at different times

Use surfaces to clarify meaning of centerlines & axes
Conceptualization

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Don’t be afraid to use simple hand sketches before delving into complex
situations … it’s NOT illegal
Simplified Representations: Performance Focused Tools
Tools to manage the type and amount
of data in session


Graphics Only Reps
•
Graphical component display only
•
No feature tree, measuring, modifications
•
Show relations, material, parameters, etc.
Master Rep of
ALL components
Geometry Only Reps
•
Graphics Rep, plus…
•
Reference and Measure capabilities
Master Rep
•

On Demand
•
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Explode, Package, Routing Apps
Automatically bring information into session
as needed, then remove
Geometry Rep
Graphics Rep
Shrinkwrap: Performance Metric
Original Transmission
File size: 147MB
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Surface Subset
File size: 23MB
Quality Level 6