Frequently Asked Questions

Q: Can't SolidWorks already do design automation?

A: Yes and no.

The power2 Assembly Generator is an add-in and is tightly integerated with SolidWorks. At the level of geometry, we can't do anything SolidWorks doesn't already do. To put it more positively, everything we do in geometry is done by SolidWorks.

We enhance SolidWorks in several key areas:

Rules:
The power2 can capture your design intent; while CAD systems just capture geometric design intent using units of quantity, angle and length, the power2 Assembly Generator captures engineering design intent in units of pressure, torque, force and many others. You can capture not just sizes, positions and counts, but the capacities and performance rationales that require them.

Automation:
CAD systems are designed to work interactively under the assumption that design knowledge is in the head of the design engineer. The Assembly Generator is designed to capture the engineer's design knowledge and automatically generate designs variations from different input specifications.

Exploration:
Computers are fast and tireless. Once you have automated your design process it is possible to explore many design alternatives and find the best design. Using the power2 Design Explorer, you can do just that.

Q: Why should I choose power2 over competing design automation products?

A: There are three main reason why you should choose power2:

Power:
Power2 can be used to capture the simplest to the most complex designs. The Assembly Generator can take you from simple parametric assembly modeling to simple configuration problems.
The power2 Design Explorer adds to the Assembly Generator the ability to explore the full range of design alternatives. No competitor has anything to compare to the Design Explorer.

Ease of Use:
Using power2's unique diagramatic modeling language, any design engineer can capture design intent to automate his design without programming. Engineering is hard, but using power2 is easy.

Price:
The Genus Assembly Generator and Design Explorer at $US 2,795 represents an unprecidented value.

Power2 includes both development and runtime environments at one low price.

Compare these prices to those of our competitors (if you can find them)!

Q: Don't all design automation systems work more or less the same way?

A: No. They don't model the same way and they don't explore (“what if”) the same way.

There are two issues:

• How do you create a design (model it), and
• How do you know which design to create explore the alternatives).

These questions are covered below.

Q: Don't all configurators model the same way?

A: No.

Design configurators employ one of two different ways of modeling; Mastermodeling or Generative Modeling.

Mastermodeling:
A mastermodel (A.K.A. master assembly) contains every possible design variation that could be created by an application. The mastermodel is refined by changing dimensions, swapping configurations, and deleting or supressing components to arrive at the final design. A Mastermodel can be managed in SolidWorks™ alone, using design tables, without the use of an add-in. More often, a third-party product adds value by providing an interface to capture the inputs and direct the changes.

While a mastermodel is a big step toward making assemblies parametric, it has some disadvantages:

• A mastermodel is necessarily encumbered by the complete information of every potential possible design alternative, even though only one alternative can be used at a time.
• Parts and subassemblies that define a mastermodel have design specific constraints, preventing their use outside the context of the mastermodel.
• If the quantity of a set of parts is a design parameter, it may be necessary to include more components than any design might ever need, and suppress or delete thode not used.
• Modifying a dimension of a "finished" model is difficult if it is controlled by a design table.
• Third party products offer no support for building or debugging mastermodels.

Generative Modeling:

• A modeling language supports creation and debugging of the engineering model.
• Rules and knowledge are organized in one location.
• Final CAD models have exactly the parts and mates they need – no more, no less.
• Parts are reusable because problem-specific constraints are not added until model creation time.
• Finished models are decoupled from the rules that created them, allowing further modification.

The power2 Assembly Generator and Rulestream employ generative modeling while DriveWorks and TactonWorks use the mastermodel approach.

Q: Don't all configurators explore (“what if”) the same way?

A: No.

Configurators do not explore the design space for alternatives. For one set of inputs, they product exactly one design. Some configurators call themselves "what if" systems since a designer can try different alternatives quickly. The power2 Assembly Generator can do this.

In a scenario where the results of a set of design inputs is not obvious, exactly the scenario that would seem to justify exploration, the designer has no guidance about whether a specific set of inputs will produce:

• a valid design
• a good design

He is exploring manually and blindly.

The power2 Design Explorer, unlike configurators, can search the space of design alternatives, eliminating invalid designs and rank ordering solutions. It conducts its search automatically, systematically, and efficiently, presenting the designer the solution set and identifying the best. While configurators do shopping, the design explorer does engineering

Q: Can the power2 Assembly Generator call legacy macros?

A: Yes. The Assembly Generator can call legacy macros in the context of a part or an assembly. It also has a general mechanism for passing parameters to macros.

Q: Can the power2 Assembly Generator reference Library Parts?

A: Yes.

Q: Can the power2 Assembly Generator set and retrieve custom properties?

A: Yes.

Q: Can the Assembly Generator be driven automatically by an outside program?

A: The power2 Assembly Generator does not yet have a documented API. However, design scenarios identified by the Design Explorer are passed to the Assembly Generator through a neutral file format we refer to as a Context File. The Context File contains one or more sets of Context Variable values used as input to an Assembly Generator project.

Any program that creates a valid Context File can use it to pass inputs to the Assembly Generator.

Q: How do I change the Configuration of a SolidWorks Component?

A: The Assembly Generator makes full use of SolidWorks Configurations, but does not allow you to directly assign a configuration name to a component.

The desire to assign Configuration names is a direct consequence of the decision to employ a mastermodel approach. The problem with this approach is that the possibilities must be predefined in the mastermodel, and the decision of which one to choose is made in the configurator system.

In the Assembly Generator, if a part has multiple configurations, you would create a unique Part Asset for each configuration. The Knowledge Diagram, which contains all the rules for existence, type, and quantity, assigns the appropriate Asset to each component. The generator, in the process of adding the component to the assembly, will select the appropriate part file and activate the correct configuration as necessary.

This keeps all the rules in the Knowledge Diagram, and eliminates the need to maintain a mastermodel.

Q: Are you telling me I can’t reuse my existing mastermodels?

A: No.

For complex mastermodels, you may choose to reimplement them generatively, just for the benefits of documentation and maintainability. However, the Assembly Generator supports the creation of an Assembly Asset, in much the same way as a Part Asset is created.

The pre-existing components of an Assembly Asset can be reparameterized, deleted, or even have their configuration changed, based on the “Exist When” rule and Part Asset type assigned to the corresponding Item in the Knowledge Diagram.

These “mini Master Models” are often used as a way of pre-orienting components. By incorporating them into a larger Generative Model, the issues of overwhelming complexity associated with a mastermodel can be avoided.

Q: I have just generated a new assembly. If I go back and change the input parameters, will the model update?

A: A SolidWorks model created by the Assembly Generator does not maintain associativity to the rules that created it. If you wish to perform a “What if” analysis, you can run the Solution again, and save the results in a different directory.

While incremental updates to the SolidWorks model make for a sexy demo, in reality they have a very limited use. For simple problems, it is not necessary to “What if”. You can be confident that the first choice of inputs is the correct one, and incremental updates are unnecessary.

For complex problems, an interactive “What if” is an ineffective way to search for a solution. There is no guarantee that your guess is the best solution, or in some cases, will even result in a solution at all.

Power2 provides the Design Explorer as the tool to systematically explore the design space, identify the valid solutions, and rank the valid solutions to identify the best alternative. When it is time to render the final design in SolidWorks using the Assembly Generator, all the guesswork is done and incremental updates are again unnecessary.

Q: How do we know if something (a single part or an entire assembly) that was generated today is a duplicate of something that was generated before?

A: The problem is the same regardless of whether the parts are generated by hand, or by a third party tool. The Assembly Generator provides no special functionality to assist with this issue, nor does it interfere with any solution you may choose to implement.

For example, when a Part Asset is created in our system, the list of parameters that uniquely define an instance of that part has been identified. Based on this, a database of existing part numbers and their parameter values could be created.

When a new part instance is generated, if its parameter values match an entry already in the database, the existing part number can be assigned to a custom property on the SolidWorks part. Any parts that do not have a part number assigned to them can get a provisional number. Whether this number is added to the database depends on your current process for part number assignment.

Q: How does the Drawing update, if it is not pre-attached to a mastermodel?

A: When a drawing is created in SolidWorks, if the parameters of the attached model are changed, the drawing updates automatically. The drawing knows which model it is attached to, because it contains a reference to that file.

The Assembly Generator simply copies a pre-existing template drawing into the directory with the newly generated model instance, and repoints its reference for the attached model to the new instance. The drawing then updates automatically to reflect the state of the newly attached model.

Q: Do Genus products use a configurator to solve design problems?

A: No. Genus does not use a “configuration engine”. Our approach to solving problems is completely different.

The issue of handling problem interdependencies occurs at two levels.

Firstly, there are dependencies between input variables. Because of this, not all combinations of inputs are valid. The goal is to start problem solving with a consistent set of inputs. This can be viewed as a very simple configuration problem, but is simple enough to solve in an interface tool. It does not require a configuration engine.

Secondly, there is the design problem. For simple problems, the Assembly Generator handles configuration issues using existence, type and quantity rules. For complex problems, the Design Explorer uses a search engine rather than a configuration engine.

Configuration engines are good for discrete, pre-enumerated problems with limited inputs and low decision branching. Such problems include configuring a computer or choosing options for a car. They are a good match to a master model because both approaches have similar complexity limitations.

Search engines can handle true engineering design because, unlike configurators, they evaluate multiple solutions, handle resource constraints and make trade-offs against conflicting goals. Search engines handle a broader scope of problems and scale better with complexity because they shift the burden of exploration and evaluation from the designer to the computer. They are a good match to generative systems because both approaches scale well.