Engineering Efficiency: How to Get More For Less

With hundreds of new automotive models scheduled to launch over the next decade, automotive manufacturers, from OEMs to suppliers are striving to streamline design and engineering to speed up new launches and keep up with the growing demand. The 2013 IHS automotive Global Light Vehicle (LV) forecast anticipates total global LV sales will increase at a CAGR of 3.9%, reaching 106.7 million by 2020.

 

What’s more, given the unprecedented launch activity surge in every industry, engineering resources are in high demand worldwide, significantly impacting R&D resource requirements in every industry. As a result, the ability to launch products quickly and cost effectively has never been more important but also never more challenging for R&D teams.

Facing the lament of reducing product life cycles as well as resource shortage, R&D is left with one choice: To improve engineering efficiency. They are tasked to aggressively improve the efficiency, reduce the rework and minimize repetitive tasks – often consuming most of their time.

Rework is probably the biggest cause of waste in the engineering process.At least 30% of product development time and effort is spent on “rework” though Engineering Changes coming from various downstream stages of product development. The Engineering Changes originating in later stages of product lifecycle are very expensive leading to delayed product launch and cost over-runs.

 

Figure 1 depicts a typical cost of design change curve for a new product design program. As you can see the cost of design changes increases exponentially as we go further in the product development lifecycle

As per our estimates, average cost of engineering change in the automotive industry can be in the range of $4000-$6000, if detected at the early design stage. A change of this scope is easier to fix at this stage, as you can do a bit of redesign and remodeling and fix it. Furthermore, if you find an error during the testing stage, where most of the errors are detected, it takes almost $40k to $ 60k to fix. As a general thumb rule the cost of making design changes increases by a factor of ten at each step of the product development process.

 

Finally, if the error gets past you into production or product has gone to market, then cost not only increases 100 times, but it can also have dire consequences in the form of costly product recalls , delays and loss of confidence amongst customers and shareholders, which is hard to quantify. Therefore, it is clear from Figure 1 that fixing errors is much more expensive and time-consuming the farther it is along it is in the product development life cycle. So the question becomes, what’s the best way to avoid changes occurring later in the product cycle?

Build efficient design and engineering process to cut down iterations

Transformations in engineering process is instrumental in eliminating waste and reducing engineering changes. Decisions made in early design stage are responsible for most of the late-stage engineering changes. Though few changes are unavoidable and arise due to factors completely outside the control of the organization like change in regulations and customer needs. However, the remaining changes can be attributed under “preventable” category which can be addressed at the early stage of product development.

Shifting from a reactive to proactive approach where designer engineers can upfront verify the impact of design decisions and identify downstream issues as early as possible in the lifecycle process can significantly reduce engineering changes and maximize efficiency. 

Our estimates show that by taking this approach, engineering productivity can be improved by 5%-15% and rework can be reduced by 6% -12% along with savings in overall cost and improved time to market.

Rework in Product Engineering- An Infographic

Engineering organization in almost all industries are dealing with costly and time-consuming design changes occurring at later stages of product development. As per our estimates at least 30%-50% of design time and effort is spent on “rework” though these Engineering Changes.

Though some design changes are unavoidable and arise due to disruptive factors outside the control of the organization such as stricter regulations and design norms, changing customer needs or product price reduction strategies etc. The remaining issues fall under completely preventable category. This info graphic helps to explain a bit about the possible causes of rework in product engineering that can be prevented and its impact on overall design time.

Learn how DFMPro® supports the Future of Manufacturing

Additive manufacturing technologies are creating a world of possibilities taking organizations in an entirely new direction and helping them rethink new approach towards product design and development.

 

Designers and manufacturing engineers are extending their capabilities as additive manufacturing offers higher design freedom and open doors to highly complex, geometric shapes and features, which otherwise would require expensive tooling to produce or even impossible to manufacture using conventional manufacturing processes. With a growing number of parts manufactured by additive manufacturing techniques, it is also important to lay down design principles suitable for such manufacturing processes as complex design features pose newer challenges downstream. Design for additive manufacturing requires multiple iterations and the availability of expertise is also limited at present. General design rules should be considered at the design stage for effective manufacturing of parts using additive manufacturing. For example some checks such as –
 
Maximum part size check – The maximum size of parts is generally constrained by the additive machines available for manufacturing. If the part is of bigger size than the allowable machine capacity, then it has to be redesigned to fit the machine. Hence it is important to know the maximum allowable size while designing the part.
 

Minimum wall thickness check – The minimum wall thickness of a part is generally constrained by the additive manufacturing method, machine resolution, etc. Very thin walls could make the part very fragile and hence it is important to check and maintain minimum distance between generic pockets (Hole/cutout/pocket) and minimum distance from edge to generic pockets to provide sufficient strength and rigidity to the part.

Eliminate Features requiring support – As additive manufacturing methods build the part layer by layer, some designs might require additional support due to the nature of additive manufacturing. Features such as negative drafts, overhangs and undercuts should be avoided wherever possible, as they require supports which increases the weight of part.

These and many other rules should be considered during additive manufacturing part designs. So does it mean that all the designs have to be validated manually for these design rules?  Although the design rules might appear simple, verifying all these rules manually in 3D models is very difficult and time consuming.

DFMPro® is keeping pace with next generation manufacturing processes to provide an automated and standardized approach. This will help designers to verify designs for additive manufacturing process and design effectively with minimal iterations and mistakes.

DFMPro is a powerful CAD integrated Design for Manufacturing & Assembly solution, which facilitates upstream manufacturability validation and identification of areas of a design that are difficult, expensive or impossible to manufacture. It supports various processes such as injection molding, casting, sheet metal fabrication, machining, tubing, sand casting and assembly.

The latest version 4.0 of DFMPro provides users much greater flexibility to design products for advanced processes like additive manufacturing, tubing to significantly reduce engineering change orders (ECOs) by getting their designs right the first time.

A quick way to get designs ready for Machining

A design engineer’s praxis in designing a product has undergone a great change in this decade. Earlier, designers were only responsible for functional requirements of the product but now they have a greater role to play in an organization – to design products which not only satisfy functional requirements but also manufacturability requirements by way of keeping product cost within the budgetary constraints and delivering innovative solutions to customers.

Functional requirements, especially for machining, translate into product design features like slots, pockets, holes, islands, grooves, profiles, etc. Design engineers have to select such features based on their prior experiences or guidelines / standards. However, when it comes to understanding downstream manufacturing capability, the knowledge is often in ‘tacit’ form. Designers have an uphill struggle in accessing this knowledge. Thus, at times the feature they add in their design is either not manufacturable or is difficult, and expensive or takes longer time to manufacture. In this case, designers may end up spending hours in design reviews with the manufacturing department or suppliers and would also have to spend considerable time in rework leading to poor design throughput. Hence, it is important that design engineers should have access to all the required downstream capability knowledge base.

Geometric’s DFMPro takes all this into consideration and capacitates design engineers to access this knowledge base, so that ‘informed decisions’ based on standards and downstream requirements can be taken. This saves a lot of effort and also ensures that design release timelines will be met and ECO/ECN instances will be reduced. 
Machining guidelines for milling cutter radius:

For designing a milled component, it is important for a design engineer to understand what cutter sizes are available with internal manufacturing or with suppliers. This is important because if the required radius is not available with the machine shop, it would lead to additional investment in buying a new cutter or at times selecting a smaller cutter which would increase the production time drastically. This becomes more important for smaller pocket radius.

In the image depicted above, the design engineer created a pocket with side radius of 10 mm. General guideline for cutter selection is as below:

“Side Radius to Cutter Radius should be between 1.1 to 1.25.”

It means that a milling cutter with radius between 8.0 to 9.0 mm should be used for milling the side radius. DFMPro can check for appropriateness of side radii based on available cutters. By configuring cutter database within DFMPro, it will check whether such a cutter is available as per the mentioned range. If the milling cutter is available as per the range, then the analysis will pass and the radius would be acceptable. If not, the analysis will fail and DFMPro will suggest the next nearest milling cutter radius tool that needs to be considered based on this, the design engineer is suggested to modify the side radius value.

For example, if a cutter is not available with radius between 8.0 to 9.0 mm, then DFMPro will automatically find out the next nearest cutter radius e.g. 9.5 mm radius tool available in database. Using this nearest cutter radius, it will find the actual side radius value which needs to be provided on the pocket/slot feature. E.g. 10.45 mm to 11.875 mm side radius needs to be provided in this case. It is normally convenient for a design engineer to modify the side radius rather than using a non-standard milling cutter with additional cost.

This way DFMPro can help design engineers by way of providing better understanding of manufacturing requirements at the right time – that is, when the design is being created. It further promotes better collaboration of design with manufacturing and captures the right understanding of supplier capability to design parts the very first time. This drastically reduces the review time and avoids rework in design. For the downstream departments, it helps reduce manufacturing time and avoid issues like tool breakage due to wrong cutter selection.