Engineers are generally not taught DFM (design for manufacturability) or concurrent engineering in college. The focus is usually on designing for functionality. Further, they are typically trained to design parts, not products or systems. Many design courses don’t even talk about how the parts are to be manufactured.
Engineering students rarely follow their designs to completion to obtain feedback on their manufacturability. Similarly, powerful computer-aided design (CAD) tools help engineers design parts, not products. Sure, CAD tools can assemble parts into products for analysis, but that does not generate the most creative product design, The most optimized product architecture. Because engineering training and tools are more adept at part design, engineers and managers tend to skip the critical concept/architecture phase and “get right to work” designing parts. This behavior is reinforced by far too many managers, who want to see “visible progress,” which may mean a quickly constructed breadboard which, after it “works,” is drawn up and sent into production.
Product development management usually stresses schedule and cost, which, if not measured right, may further reinforce all the above suboptimal behavior. Pressuring engineers to complete tasks on schedule is really telling them to just throw it over the wall on time.
In reality, the most important measure of schedule is the time at which the product has ramped up to stable production and is satisfying all the customers who want to buy it.
# Design for manufacturability (DFM)
The process of proactively designing products to (1) optimize all the manufacturing functions: fabrication, assembly, test, procurement, shipping, service, and repair; (2) ensure the best cost, quality, reliability, regulatory compliance, safety, time-to- market, and customer satisfaction; and (3) ensure that lack of manufacturability does not compromise functionality, styling, new product introductions, product delivery, improvement programs, or strategic initiatives and make it difficult to respond to unexpected surges in product demand or limit growth.
# Concurrent engineering
The proactive practice of designing products in multifunctional teams, with all specialties working together from the earliest stages. DFM and concurrent engineering are proven design methodologies that work for any size company. Early consideration of manufacturing issues shortens product development time, minimizes development cost, and ensures a smooth transition into production for the quickest real time-to-market.
Before DFM, the motto was “I designed it; you build it!” Design engineers worked alone or only in the company of other design engineers in “the engineering department.”
Designs were thrown over the wall to manufacturing, which then had the dilemma of either objecting (“But it’s too late to change the design!”) or struggling to launch a product that was not designed well for manufacturability. Often this delayed both the product launch and the time to ramp up to full production, which is the only meaningful measure of time-to-market.
Top 4 Myths and Realities of Product Development…..
Resistance to DFM may stem from myths about product development. Here are the most common myths and the corresponding realities:
- Myth #1: To develop products quicker, immediately move forward with detail design and software coding, and then enforce deadlines to keep design release and first-customer- ship on schedule.
- Fact: The most important measure of time-to-market is the time to stable, trouble-free production, which depends on getting the design right the first time.
- Myth #2: To achieve quality, find out what’s wrong and fix it.
- Fact: The most effective way to achieve quality is to design it in and then build it in.
- Myth #3: To customize products, take all orders, and use an ad hoc “fire drill” approach.
- Fact: The most effective way to customize products is with the concurrent design of versatile product families and flexible processes. This is known as mass customization.
- Myth #4: Cost can be reduced by cost reduction efforts.
- Fact: Cost is designed into the product, especially
Some Comments from Company DFM Surveys..
The following are verbatim comments from company surveys before DFM training. Then asked about the consequences of inadequate DFM, engineers and managers usually cite problems with quality, cost, delivery, profits, and competitiveness.The colorful comments convey what it is like to work in a company that does not design products well for manufacturability.
The consequences of inadequate DFM for delivery are
- “Line stoppers”
- “Parts do not assemble correctly”
- “Endless engineering change orders”
- “Much pruning, grooming, and tuning to get products out the door”
- “Poor yield invariably results in late delivery or 11th-hour miracles”
- “When a problem is encountered the production line comes to a stop”
- “Emergency change orders and redlines to keep manufacturing operating”
The behavioral hurdles to good DFM are
- “Lack of DFM training,” “Lack of DFM knowledge”
- “Parts designed with no consideration of how it is to be built”
- “‘Over the wall’ syndrome: after release, no longer engineering’s
- “Never enough time to design parts right the first time; always enough time to do it over”
The attitude hurdles to good DFM are
- “Designer’s limited knowledge of manufacturing processes”
- “Reluctance to accept suggestions from suppliers regarding design issues”
- “We don’t seem to allow time to design systems properly upfront, but we are willing to do it over later after a product is released”
The bottom line consequences, besides profitability, include:
- “Unhappy customers”
- “Sometimes problems get shipped to the field”
- “Customers losing confidence in our products”
- “Problems increase overall costs, resulting in loss of the ability to compete”
- “Low product quality leads to poor customer satisfaction, poor performance, and eventually to high costs”
- “Post-launch redesigns”
Major Roles & Focus area
Optimal company performance comes from whole-company synergy, where the whole company works together to develop products for manufacturability:
Engineering and manufacturing concurrently engineer products and processes, Marketing works with the team from the earliest stages to define whole product families that satisfy the “voice of the customer.”
The purchasing and materials groups support product development by nurturing vendor and partner relationships instead of looking for the lowest bidders;
taking pressure off product development teams by shortening procurement times; encouraging part standardization; and prequalifying parts and vendors to optimize quality and delivery.
Finance quantifies total cost to support relevant decision making and arranges for appropriate overhead charges for new-generation products. A DFM task force incorporates DFM steps into the product development process and creates, issues, and updates a consistent set of design rules and guidelines.
Learn more in Job Rotation
Company policy should also arrange job rotation to encourage cross-learning and informal communications, starting with placing new design engineers in manufacturing first. It can be argued that it takes new employees’ time just to learn their way around the company, and engineers on their first job need to learn even more. So while they are getting up to speed on how the company operates, they can be learning about the company’s manufacturing practices.
“At tata motors, all entry-level engineers spend their first three months in the company working on the assembly line. They’re then rotated to the marketing department for the next three months. They spend the next year rotating through the engineering departments—drive train, body, chassis, and process machinery. Finally, after they have been exposed to the entire range of activities involved in designing and making a car, they are ready for an assignment to an engineering specialty, perhaps in the engine department.”
Management Role to Support DFM
Senior managers and executives should understand these principles enough to execute the following advice.
- Plan the product portfolio and its evolution over time objectively to provide the greatest net profit over time, defined as all the financial gains minus all the costs.
- Don’t spread resources too thin by “taking all orders.” Focus on selling the most profitable products and rationalizing away the “losers.”
- Ensure resource availability so that complete teams can form early. Don’t waste product development resources trying to reduce costs after the product is designed. Preselect vendors so they can help the team design the parts they will build, which saves much more money than bidding.
- Have realistic expectations compatible with the product development methodology.
- Encourage a high proportion of thorough up-front work through good product definition, early issue resolution, concept simplification, and architecture optimization. Avoid early deadline pressure that thwarts thorough up-front work.
- Implement total cost measurements to enable prioritizing all activities, planning product portfolios, rationalizing products by real profitability, and relevant decision making.
- Follow through so the team is responsible for transition into production and the team stays with the project until production has stabilized in volume, productivity, and quality.
- Empower an effective project leader to make decisions as they need to be made, thus minimizing dependence on design reviews.
- Encourage feedback and be receptive to all news about product developments. Create an open culture where issues can be raised and discussed early with the focus on issue resolution.
Majorly Management Focus
Senior managers and executives should focus on the following:
- • The activities and methodologies that lower cost and speed development, instead of relying just on goals, targets, metrics, reviews, gates, and deadlines. It is important for product development teams
- to have the right focus when developing products.
- • Customers’ needs, not on the company programs, competition, or technology.
- • Proactive resolution of issues early rather than reactive resolution later.
- • Problem avoidance rather than problem solving.
- • Eliminating engineering change orders rather than streamlining the change control process.
- • Core competencies and new and pivotal aspects of the design instead of reinventing the entire wheel and diluting resources with low-leverage activities.
- • Product and software architecture, not just drawings and code.
- • The design process itself, not on project control and management.
- • How to optimize activities in the phases, not the gates or design reviews.
- • On-demand discussions and decision making, not periodic meetings and reviews.
- • Product design, not proofs-of-principle, breadboards, and prototypes.
- • Optimizing product architecture, not just designing a collection of parts and subassemblies.
- • Rapid production ramps in real production environments, not pilot production by prototype technicians or engineers.
- • Time-to-stable-production, not time-to-design-release or first customer-
- • Minimizing total cost, not just reported costs (labor and materials).
- • Designing and building in quality and reliability, not by testing, inspections, or reacting to field problems.
- • Compensation systems that encourage behavior that benefits the company, not departments or individuals.
- • Activities that achieve major and lasting cost reduction (superior product development, Lean Production, quality programs, etc.), instead of cost reduction attempts that may compromise real cost
- reduction and delay the time to stable production.
COMPANY BENEFITS OF DFM
The following slogan sums up the importance of DFM:
- Functionality gets us into the game;
- Quality and reliability keep us in the game;
- Manufacturability determines the profit.
And yet most engineers and managers focus primarily on functionality. In order to stay in the game, products need to be produced with high quality and reliability. And what about profits? Unless the product has a formidable head start or incredibly strong patents, the product will have to be priced competitively, which then means that profits will be determined by the cost.
it is very difficult to reduce cost by “cost reduction” efforts after the product is designed.Therefore, profits are determined by how well low cost can be assured by design—that is, designed for manufacturability.
The benefits of DFM range from the obvious cost, quality, and delivery, to some important subtle benefits:
• Lower production cost. Designing for simplicity, fewer parts, and easier assembly results in lower assembly cost. Lower cost of quality results from fewer parts and foolproof assembly. Smoother product introduction means less time spent on costly change orders and firefighting to deal with product introduction problems.
• Higher quality. Higher quality results from more robust designs, fewer parts, foolproof assembly optimal process selection and design, the use of more standardized parts with known good quality, and designing around proven engineering, parts, modules, and processes.
• Quicker time to market. DFM products fit better into existing processes and are less likely to require special equipment and procedures. The use of standard parts means most will be on hand or be easy to procure. Better DFM means fewer product introduction problems, leading to a quick and smooth introduction.
• Lower capital equipment cost. Designs that assemble easily need less time on assembly machinery. Less need for special equipment saves equipment capital. Designing to minimize setup and the use of standardized parts result in fewer setup changes, thus leading to greater machinery utilization.
Greater automation potential. Designing for automatic assembly maximizes the potential for automation, with all its cost and quality advantages.
• Production up to speed sooner. Faster development, fewer introduction problems, and less need for special equipment or procedures result in production that will be up to speed sooner.
• Fewer engineering changes. Early adjustments are much easier to make than later changes that are under change control procedures. If the original design satisfies all the goals and constraints, it will not have to be changed or redesigned for manufacturability or any of the other design considerations.
• Fewer parts to purchase from fewer vendors. Having fewer parts to purchase saves purchasing expense, especially for standard parts. Dealing with fewer suppliers strengthens relations with those suppliers and results in less cost and effort to qualify parts and deal with quality problems.
• Factory availability. Fewer production problems and greater machine tool utilization make factories more available for other products.