Your Best Source for CAD, CAM & CAE Articles

| About | Submit Article

CADdigest Weekly
Email (required) *

A week's worth of articles will be emailed to you. See latest issue .

CAD, CAM & CAE Articles



More News



  Independent Content    

Rulestream Engineer-To-Order

By Ralph Grabowski, Oct 22, 2012

CAD software is used to design products with varying variability, in a range that director of Rulestream products Brian Grogan describes on a five-point scale:

As you go from top to bottom on the list, more engineering is needed during the sales and order fulfillment processes; Rulestream software from Siemens PLM Software best fits the last three on the list, and the ETO (engineer to order) category most of all.

Working on ETO projects can become problematic when long lead times develop from designing products that don't even exist. In these cases, cost estimation and some design most likely is being done from scratch; in any case, new ETO projects can involve guesswork stemming from a lack of time and other resources during the proposal process. Proposals can lack product data required for buyers to fully understand what is being proposed. For instance, 3D visualizations these days are becoming a normal request from clients, but at the time of inquiry the 3D model hasn't been designed yet!

As the design is fine-tuned to meet customer specs, the work becomes iterative, and then the specs themselves can change over time. Delivering late might result in financial penalties. Errors in engineering release data (drawings, BOMs, and so on) lead to manufacturing scrap and rework. And today design teams sometimes are located "anywhere," leading to the need to communicate between offices

Rulestream is meant to solve these problems. It is used in the tasks found in the orange and green boxes of figure 1.

Figure 1: Example engineer-to-order process with Rulestream
The Aim of Rulestream

The aim of Rulestream is to allow firms to respond to the market with ETO products at nearly the same speed as standard products, while at the same time improving accuracy. It helps you go directly from order to manufacturing - except for truly custom designs.

But isn't this the purpose of PLM [product lifecycle management], you might wonder? True, but Rulestream has additional functions lacking in PLM. While PLM can manage data, workflows, BOM, and cost estimates, Rulestream automates many ETO processes that feed data to the PLM system.

(Competitors to Rulestream include aging home-grown systems developed with custom programming, and simple sales configurators applied to ETO, like the Dell example.)

There are two groups of "typical" industries using Rulestream, those who were a focus historically, and new ones. The software has been used in heavy duty industries, such as power generation and distribution, HVAC&R [heating, ventilating, air conditioning, and refrigeration], commercial and specialty vehicles, and the oil and gas industry.

But since Rulestream was acquired by Siemens, it is also focusing on additional markets, due to the industries in which Siemens itself works. These include consumer package goods, medical devices, and utility EPCs [engineering, procurement, construction].

Let's take a look at a specific user case. Babcock & Wilcox builds power generation plants and equipment, and has been using Rulestream for ten years now. The plants are not the result of push-button design, but consist of complex systems that take a long time to design. When the company applied Rulestream to several of its product lines, the time to develop proposals dropped from weeks to days. For some products, proposal design time was reduced by 80%.

How Rulestream Works

So, what is it about Rulestream that allows an 80% reduction in design time? During design, there is some repeatability; just think, for instance, the tedious jobs of applying dimensions and filling out title blocks. Rulestream captures the "recipe" for processes, and then its rules drive native authoring tools, like CAD software, Microsoft Office programs, and PLM applications.

Rulestream replaces the engineer's need to do repetitive work; it automates things to the largest extent possible. Where you get that 80% efficiency rate quoted above is from processes that have high amounts of repeatability. Rulestream can automate the following areas in engineering firms:

Figure 2 shows a typical rich client interface for a Rulestream application. The user interface is configured by each company to meet the needs of its users. This particular screen captures some of the top level inputs required to configure a rack of refrigeration equipment (number of compressors, and so on) required for a new grocery store. After the user enters the number of refrigerated displays needing cooling, Rulestream reports

  1. The amount of compressor cooling capacity needed...

  2. ...which determines the number of compressors needed...

  3. ...which determines the number of racks required...

  4. ...which determines the amount of floor space needed.

Figure 2: Typical Rulestream interface, as seen by users

All this can be configured through formulas and tables in Rulestream, because all grocery stores have similar cooling and freezing requirements; it's just the amount and location that varies.

Once the number and arrangement of compressors is satisfactory, Rulestream generates parametric CAD models from templates stored in PLM or a file repository. Rules determine which parametric model templates to use; they size the models based on rule-calculated values; and they even can build assemblies dynamically from the bottom up. When generating 2D drawings, additional rules determine dimensioning, the scaling, the number of sheets, filled-in title blocks, and so on.

Rulestream works with most of the important MCAD programs; these appear inside Rulestream, or else can pop out and run in an independent window. See figure 3. If a CAD license is not available on the local machine or direct editing of the CAD model should not be allowed (the case with a sales person), then the CAD model is generated on a server and the JT viewer displays the 3D model. (JT is Siemens PLM Software's open 3D visualization format supported by many MCAD programs.) Autodesk's TrueView is used to display DWG files.

Figure 3: CAD program running inside Rulestream

Often customers use Microsoft Visio for layouts and logic diagrams; rules are mapped to shapes in Visio so that Rulestream can determine whether rules are being followed during diagramming.

Rulestream can take data feeds from CRM [customer relationship management], ERP [engineering resource planning], and databases of similar software to get information, so that you don't need to reenter the data manually.

Rulestream has rules to generate BOMs by querying a database of part numbers; for custom parts, Rulestream generates the new part drawings and part numbers based on rules - or else if no rules, then the parts have to be added manually. Once the BOM is generated, it is sent back to the PLM or ERP system for lifecyling and downstream processing. In addition, Rulestream generates schedules, proposals, and quotation documents in Microsoft Word, as shown in Figure 4. These documents incorporate images of configured products automatically.

Figure 4: Microsoft Word document generated automatically by Rulestream
Configuration by Customers

One of the scary parts in the early days of rules-based systems was the amount of programming needed to create something that worked for your firm. This drawback has been overcome through Rulestream Architect, an authoring environment that allows you to create your own rules; you don't need to know complex programming, CAD or Visio APIs, or even UI programming.

Most new Rulestream customers require some level of support on their first deployment. Throughout deployment, support from Siemens PLM Software includes training, mentoring on best practices, and active coaching and support on rule entry. Siemens usually staffs 10-30% of the effort on the first project, depending on the size of the project and customer own resources; on subsequent projects, customers are usually able to handle 100% of the implementation themselves.

The work begins by classifying groups of rules that apply to the product or the process. Types of rules captured can include rules for design, design for manufacturability, compliance, cost, shipping - any rules that accurately configure products. Rules are organized in a relational database so that they can be organized and managed. Rulestream includes a history that records everything done, so that you can check if who edited each rule, and if it was miswritten.

Siemens PLM Software does not supply content like rules or parts, such as ASHRAE rules. Default values can be determined, however, from the geometry of CAD models, including parametrics. In some cases, manufacturers might provide rules with their parts. And some customers are looking at their assisting their OEM clients by providing the rules they wrote in Rulestream.


Rulestream from Siemens PLM Software is particularly meant for custom product manufacturers who need a way to more quickly respond to custom orders. Once rules and other data are in the Rulestream system, they are reused to further automate engineering processes. By capturing engineering knowledge in the form of rules, Rulestream automates specific processes for entire businesses by integrating with CAD, PLM, and ERP systems.

See All Independent Content | Back to Top

Additional Information

Back to Top

About the Author

Ralph Grabowski, TenLinks managing editor, is one of the leading CAD journalists and authors, with over a 100 books and many hundreds of articles. His upFront.eZine may be the industry's longest running newsletter. Ralph holds a civil engineering degree. More...

About Independent Coverage

TenLinks uses over 125 expert authors for unprecedented coverage of CAD, CAM, CAE products and services. Find out more about Independent Content and apply for coverage.