In the never-ending quest to improve quality and shorten lead time, engineer to order (ETO) manufacturers are finding that a rules-driven approach to automating key design, engineering, and manufacturing processes can significantly streamline their operations. An evolution of older knowledge-based engineering (KBE) implementations, rules-driven product management (RPM) offers significantly streamlined engineering rule capturing and reuse capabilities.

First, some do's and don'ts:

• Do focus on business value . . . Whether it's increasing revenue, increasing net profit, expanding geographically, or adding new products, make sure your RPM implementation supports those corporate objectives.


• Don't worry about all the rules . . . You don't need to determine ALL the rules initially. What are the basic rules to solve your problems? You can easily add or edit rules later -- pushing them out to the workforce in real-time.


• Do identify good products/systems for RPM implementation . . . Which of your highly complex products or systems do your customers frequently ask you to customize? You benefit more by automating the time-consuming, routine engineering and manufacturing tasks in these high margin orders.


• Don't solve just engineering problems . . . Rules can be anything from equations to common sense. Don't forget about sales and manufacturing requirements.


• Do identify the specific processes to be improved . . . Map out a day in the life of a custom order.


• Don't create specific product configurations ahead of time . . . Let the rules create your models and engineer new product variations on-the-fly according to actual requirements.

Designing a Bicycle

In the following example, we will use RuleStream Architect and RuleStream Engineer to define, enforce, and repeat some key engineering rules surrounding the design of a custom-built bicycle. We'll show how this process works, illustrating the automation of some of the routine and repetitive tasks of product engineering. We'll begin our project by launching RuleStream Architect and opening an existing rules database that is tied to our bicycle CAD model and drawings (created in SolidWorks).

1: Create & Enter Rules -- Acting as a design engineer and subject matter expert on bikes for the first two steps, we are going to add a rule that governs the clearance between the front tire and the bike frame to our existing bike rules database. A simple user interface allows subject matter experts, not necessarily programmers, to enter rules. Using the formula editor, we input a new key design parameter: a new rule. We have received feedback from our manufacturing engineers that they would be more comfortable if they had more room to work with around the tires, so we will add 25% to the minimum front tire clearance calculated by RuleStream. We enter the formula

"result = this!MinimumFrontTireClearance*1.25"to effect this change. Any supporting documentation can be added to explain the reasoning behind the new rule. A rule history is also generated.

2-1: Set Up the User Interface -- Now that we have a new rule to work with, we need to update the bike user interface that will appear in RuleStream Engineer. RuleStream Engineer will be used by design engineers at the point of sale to enter custom configuration requirements from the customer. Updating the interface in RuleStream Architect is easy. First, using the front tire clearance as an example, we specify that this value will be visible to and editable by the user. The default value will be the value calculated from the rule we specified in the first step. We can constrain what the user enters for the front tire clearance by specifying minimum and maximum values (which could also be calculated by rules) or predefined values from a list.

2-2: Generate the User Interface -- Next, we open the user interface wizard, identify which fields we want to expose to the end user, and generate the UI.

3: Use Option 2: Sales and Manufacturing Customization -- Now that the rule has been defined and the user interface has been updated, we can exit RuleStream Architect and launch RuleStream Engineer. In the next phase of the process, we play an engineer who works closely with the sales team to manage order specifications and manufacturability. We need to enter the size of key individual parts, such as wheel and frame size and handlebar configuration, that will affect the cost of the item (even the shipping), based on customer requirements. The sales engineer would launch RuleStream Engineer and create a new order. RuleStream Engineer would then present the user with the screen seen in Figure 3 for the bike. The user can then follow the process steps down the left side of the UI to define the customer's requirements. Each step will display a different UI for the set of rules involved. We enter our customer's weight as 180 lb, the required reach of 24 in., a tire size of 28 in., and an inseam of 35 in. We click on the Update Model button and a new model is instantly generated.

4 : Generate a Proposal and Manufacturing Documentation -- With all the necessary specifications entered, we can now generate a variety of drawings and other supporting materials, for both internal and external use. In Figure 4 we see the process step selected that displays a proposal to the user. This proposal can be saved and printed out or emailed to the customer. Other output can include detailed engineering drawings, detailed BOM and other engineering information, plus 3D models, cost estimates, color product mockups, and proposal documentation are available immediately. These documents are created automatically based on the customer requirements, automating the repetitive and routine tasks that engineers are often required to do. Complete, accurate proposals are generated faster with fewer errors.

5: Change a Parameter -- The customer has come back to us and asked us to tweak one of the design parameters -- we've received new information about the customer, and need to change the tire size information. We go back to the process tree, select Base Design, change the tire size to 30, and click on the Update Model button to regenerate the drawings and all supporting documents. In our old engineering environment, usually even a simple change request like this could take hours or days to complete, and even more time to update the associated documentation. In this case, since the rules and interdependencies are established in the system, changing the size of the tires dynamically updates the bike with a stronger frame rated for that weight. Everything from our engineer proposal to our manufacturing drawings is automatically updated to reflect this change.