Design for Manufacturing: Getting it Right the First Time Pays Off

By May 22, 2018 April 26th, 2019 Manufacturing
Suprematist Composition (Kazimir Malevich, 1916)

Competing in a Global Market – What’s Your Competitive Advantage?

Today’s global marketplace gives companies access to more customers and greater growth possibilities. But to succeed in a crowded, hypercompetitive market requires companies to outperform the competition in speed to market, product quality, competitive pricing, and strong margins.

Traditional product leadership tends to focus, not unreasonably, on competitive functionality and cost. But all too often management neglects to consider the far-reaching impact that suboptimal design could have during prototyping and manufacturing volume ramp up.  Whether because of time pressure, lack of experience, or just complacency, many product organizations often ignore downstream manufacturing during product design.

Study after study shows that inept design for manufacturability leads to unnecessary engineering changes, slower time to market, and higher manufacturing ramp up costs. Meeting project schedules, achieving a high level of quality, and controlling production costs are highly dependent on getting designs right the first time.

Design for manufacturing (DFM) practice strives to optimize product design by applying rigorous design checks and automating verification tasks to validate manufacturability, and identifying areas that are difficult, expensive or even impossible to manufacture. Checking designs for manufacturability early in the design phase is essential to achieving high quality, reducing errors and rework, and controlling production schedule and costs.

In this two-part article, I will discuss two global manufacturers that have adopted a design for manufacturing culture and their experience in implementing a formal DFM process.

Design Mistakes Go Undetected

A European maker of semiconductor lithography system used by global chipmakers experienced early phase manufacturing problems. Manufacturing snags, requirements that do not match supplier capabilities, and similar issues that led to early quality glitches were not identified during design reviews and were discovered only during assembly and field testing. The large number of engineering changes delayed order fulfilment and increased internal costs.

A global manufacturer of a broad portfolio of medical imaging and therapy equipment experienced similar woes:  simple design mistakes such as drilling a hole too close to a wall passed multiple design reviews, and, like the semiconductor equipment company, the company was faced with a growing number and cost of seemingly avoidable change orders.

Why do simple design errors and obvious violations of manufacturing rules go undetected repeatedly during formal design reviews??

Many design engineers do not possess practical manufacturing processes knowledge and experience. They focus on optimizing functionality and reducing product cost, but don’t have the knowhow and tools that let them consider the ramifications of design decisions on downstream manufacturing processes.

Today’s products involve a broad range of engineering and manufacturing disciplines. Design engineering must be proficient in multiple manufacturing disciplines: injection molding, milling, turning, and forming. And additive manufacturing and composite materials—both relatively new manufacturing disciplines with additional manufacturing rules and constraints—only add to the pressure.

As a product manager put it: “design engineers do not appreciate the manufacturing process. They are not very good in using CAD design-check tools either.”

In fact, CAD-based checks aren’t always sufficient to detect subtle mistakes. For instance, one of these companies discovered that a design for a cooling water manifold specified wall thickness that was well within the required tolerance, so it was approved at a critical design review. However, normal manufacturing process variations caused it to fail during quality assurance tests.

Moreover, some manufacturing organizations do not have the appropriate data foundation for more advanced manufacturability checks. Despite progress in CAD and 3D modeling, manufacturing data in many organizations, especially in established, long-running companies, are still using 2D drawings for design reviews, which makes manufacturability validation very difficult.

Design for Manufacturing in Practice

HCL’s DFMPro,  available for popular CAD packages NX, Creo & SolidWorks is a manufacturability validation tool that automates validation checks and allows designers and manufacturing engineers evaluate design models for manufacturability and assembly. The software includes checks for a broad range of manufacturing processes such as injection molding, machining, sheet metal fabrication, casting, and assembly.

Product companies use DFMPro to formalize and automate the design review process for manufacturability. Using design rules and best-practice knowledge, the tool accelerates the identification of problems and suggests corrective actions. Not only are mistakes caught early in the design process, but newly discovered issues are added to the knowledge base so that past mistakes are not repeated.

The companies I spoke with took a cautious approach to introducing the use of DFMPro. Its use is not mandatory, but design engineers are strongly encouraged to use it to review and check part designs. Product teams use it as a formal design review phase gate. Design engineers use manufacturability evaluation report as part of the gate review process.

As the use of DFMPro is voluntary (although common), some early adopters have not engaged in formal measurement of its business impact. But both teams are confident that when used, DFMPro improves manufacturing ramp-up time, tooling, and order fulfillment. They believe the systematic practice of design for manufacturability reduces the number of iterations with suppliers, quality defects and warranty claims.

Image: Suprematist Composition (Kazimir Malevich, 1916)