Influence of Furniture Appearance Design on Product Cost
——Taking the Utilization Rate of Upholstery Materials as An Example
The main content is in the early stage of new product development, through the cost-oriented design method, reasonably select the design scheme, and control the product cost.
Methods: Using three-dimensional design software, virtually simulate different design schemes, and calculate the impact of fabric or leather nesting results on product cost under different schemes.
The result shows that the slight difference in appearance design of 16mm will lead to a difference of 0.7% in the utilization rate of fabrics and 0.73% in the utilization of leather.
The conclusion is that in the early stage of new product development, the use of computer-aided design software 3D modeling and simulation calculation will have a multiplier effect on cost control in the product life cycle.
Furniture Background introduction
Furniture, the ancient industry began a special development process with the pace of world industrialization since the middle and late 19th century. Today, the division of labor in this industry is constantly refined, collaboration is frequent, and competition is fierce. Since the reform and opening up of China’s furniture industry, the total industry output value has increased at a rapid rate of 15% per year. In 2005, China’s furniture export exceeded Italy and ranked first in the world. While in 2013, the total output value of China’s furniture exceeded trillions, accounting for 1/4 of the world’s total.
However, like other labor-intensive industries in China, the rapid development of the furniture industry is mainly reflected in the growth of quantity and expansion of scale. In the layout of the industrial chain, most of China’s furniture enterprises are still in the manufacturing process. After years of development, enterprises have a complete supply chain of raw materials and high-quality labor, thus forming a competitive advantage with low prices as the core.
Development status of China's furniture industry
With the following situations:
- soaring prices of raw material supply, shipping logistics, labor costs, etc.,
- the government’s strict requirements on enterprise energy consumption and environmental governance
- the state’s control of the direction of industrial upgrading
Furniture companies need to learn from the experience of high-end manufacturing such as automobiles and electronics in the product development stage. By changing ideas, standardizing the modular development process, and introducing new tools and technologies, improve the development efficiency, thereby enhancing the core competitiveness of products. And these are crucial to the long-term sustainable development of the enterprise.
Challenges and Opportunities
Today, most enterprises are developing in the direction of intelligent manufacturing. Whether or not to use digital development tools in the research and development stage of furniture enterprises is no longer a question of judgment. Choosing the right development tools and making the tools fit with the company’s own business model is the key. The core technology of digital research and development is Computer Aided Design (CAD). It is a computer application technology that uses the computer’s fast numerical calculation and powerful graphic and text processing functions to assist engineers and technicians in product design, engineering drawing and data management.
CAD technology has been widely used in the product development stage of machinery, automobiles, electronics, clothing, construction and other industries. While the application in the furniture industry, especially in the upholstered furniture covered with soft materials, is still in its infancy. Leading companies have invested resources to explore and create standard processes for digital product development together with relevant technology providers. Small and medium-sized furniture enterprises are also actively seeking digital R&D solutions in the market, hoping to achieve corner overtaking through rapid technological upgrades.
In traditional product management, the control point of cost is often concentrated in the process of material procurement and product production. In modern product life cycle management theory, with the concept of cost-oriented design (Design for Cost, DFC), It is required to fully consider the control of product cost from the stage of design planning and R&D proofing. It’s to balance the appearance, function and cost of the product, and to find the best balance between the company’s profit and the value provided to customers.
Fabrics and leather materials are widely used as raw materials in the upholstered furniture industry. Due to factors such as huge usage and complex upstream and downstream supply chains, the utilization rate of materials has become the key for enterprises to control product costs.
This article is based on the 3D design software of Lectra, and takes a soft furniture product as an example. It describes that under the cost-oriented design concept, how to use software tools to simulate the impact of different design schemes on product cost in the product design stage, and start to control product cost in the early stage of product life cycle.
3D modeling of products
For the furniture industry, the digital upgrade of product development is based on the product virtual modeling and simulation analysis. The application of these technologies in relatively advanced industries such as automobiles, electronics, and machining has been very mature. But the furniture industry is still in its infancy.
Especially for the sub-category of upholstered furniture, due to the 2 reasons:
- particularity of its product design and market demand
- the technical background of practitioners
The choice of software tools often requires careful consideration of the fit with the business demands and product development models of enterprises.
The main content of this article is the influence of different designs on product cost based on the existing 3D digital model. So the 3D modeling will not be described, and only the 3D model of the product (Figure 1.1) will be used to illustrate the products involved in this paper.
This product example is different from traditional upholstered furniture. The internal manufacturing process is similar to that of car seats, mainly metal structure and foaming process. While the external cover is completely sewn by traditional sofa technology. And the cover can be made of artificial materials such as technical cloth or PU, or leather materials.
Different options for upholstery design
In the appearance design of this product, the curves and curved surfaces are very characteristic. In addition to the overall curve design, there are two important “soul lines” in the design of the split lines. One is located on the side of the product, outside the armrest. While the other is located on the upper part of the product, at the junction of the armrest and the backrest. When the designer made the split line design on the upper side of the armrest, there were two schemes A and B as follows (Figure 2.1):
The yellow branch line is the A scheme, and the green branch line is the B scheme. From a visual point of view, the curvature of the parting curve of scheme A is more complex. Although it can make the product shape more flexible, it also increases the difficulty for subsequent production. While scheme B only slightly adjusts the parting curve of A in the part with large curvature. In terms of space, the maximum distance between the two solutions is only 16mm, and the lines in other parts of the product remain exactly the same.
In terms of appearance, the maximum distance of 16mm between the two solutions of AB will not visually cause obvious difference. However, it’s such a difference will cause a huge difference in subsequent production and product material cost. From the point of view of production process, the relatively simple segmentation must bring about simple process and stable quality. From the perspective of product cost, we look at the benefits of design for cost from the perspective of artificial fabric and natural leather layout.
Use the automatic “flattening” function of the software to perform the flattening operation from the three-dimensional surface to the two-dimensional template for the two surface cover design schemes A and B respectively, and obtain the following plane template (Figure 2.2). Since the two sets of designs are completely the same except for a slight difference in one line. It is difficult to distinguish the difference between the two-dimensional templates obtained by flattening without careful comparison. The left and right matching patterns in each set of patterns only show one piece on one side, but during the nesting process, two pieces participate in the subsequent nesting calculation.
The influence of the design scheme on the discharge utilization rate
Comparison of the utilization rate of man-made fabrics
In the calculation of the fabric layout comparing the two design schemes A and B, use the exact same fabric width, number of nesting sets, nesting time and other nesting parameters. Then, the software automatically calculates and gives the layout utilization rate (Take the layout of 5 sets of products as an example), as shown in Figure 3.1.
The fabric layout utilization rates of the two schemes are 85.0% (A) and 85.7% (B) respectively. Although the difference of 0.7% is not large in number, if this figure is applied to large-scale mass production, the resulting cost difference will be huge.
Comparison of utilization rate of natural leather material
The parameters involved in the nesting of genuine leather are more complex. To better control the product cost, it is also necessary to consider the leather of different quality corresponding to different areas on the product sample. And the leather itself also has different material defects.
As shown in Figure 3.2, according to the product design, the template defines different cortical partitions according to different parts. And they will be displayed in different colors. For example, the best leather (yellow) is used on the top and side of the armrest and the front of the backrest. While the slightly worse leather (blue and green) is used on the inside of the armrest, and the worst leather (red) is used in the stitching part of the sample. ).
In the leather nesting simulation of the software, like the fabric nesting, we also adopted the exact same nesting parameters for the two design schemes A and B. It includes:
- selecting the exact same leather material to ensure that the distribution of defects and skin areas is completely consistent
- set the same nesting strategy and nesting calculation time, etc.
The leather nesting result is shown in Figure 3.3 (take the nesting of 5 sets of products as an example).
The software shows that the nesting utilization results of the two design schemes A and B respectively are 78.98% and 79.71%. The 0.7% difference in fabrics may not have a significant impact on costs when the product output is not high. But the 0.73% difference has a huge impact on product cost in the case of high leather prices and mass production of products.
The cost of the leather used in the mid-to-high-end leather sofa is about 15 yuan per square foot. Taking this sofa as an example, the software calculates that 5 sets of product layouts use a total of 139.065 feet of leather. According to the leather saving of 0.73%, the average leather saving per sofa is calculated as:
If the output is 100,000 sets, this subtle design optimization can save more than 300,000 yuan of leather materials. Or we can say this 16mm design optimization saves more than 20,000 feet of leather raw materials for the production of this batch of products. If you carefully consider the parts that can be optimized in the product, there must be more than one here. In addition, among all the products being developed by the company, there must be more than one product that can be optimized for design.
Of course, this assumption only takes into account the cost savings of the raw materials themselves. If other costs such as production labor, logistics, warehousing and management related to more than 20,000 feet of leather are further considered, no company will reject this “16mm”.
Advantages of parametric design tools in cost-oriented design
The layout of the template above is based on the unfolded surface template of the 3D digital model of the product. The three-dimensional design can use direct modeling or parametric modeling.
Direct modeling is more used for quick modeling, which can easily and quickly produce the desired product design effect. But the disadvantage is that it cannot deal with the relationship between features. And only the selected surfaces on the model can be modified one by one. Direct modeling allows for faster manipulation of the design, so it’s convenient at the beginning of a project concept.
But if the purpose of the design is for the subsequent manufacturing process, product cost control, production quality control and product digital management, the output of the design requires stricter technical accuracy, more detailed technical details and better project visualization. Under this premise, a parametric modeling approach that emphasizes standardization and modularity is a more appropriate solution.
Parametric design is a design process in which the design itself is written as a digital model (function). Besides, the design process is automated by modifying the initial conditions and design constraints, and obtaining engineering results through computer calculations.
The following contents included in the above product examples are all completed in Lectra’s cost-oriented 3D software solutions.
- appearance digital 3D modeling
- design of the cover line
- automatic flattening of the 3D cover
- simulated nesting on artificial fabrics and genuine leather with different pattern schemes
- analysis and calculation of relevant nesting utilization rate
Under the scheme based on “parametric design”, the difference between product design schemes can be displayed “quantitatively and intuitively”. What’s more, the design changes on the digital model are automatically calculated by the software and the analysis results are quickly given. Such design logic enables the entire product development process to be digitally improved. More than that, the product development projects are visualized, predictable, and closely linked to product costs.
The layout of the template above is based on the unfolded surface template of the 3D digital model of the product. The 3D design of the product can use direct modeling or parametric modeling.
If the mass production of products emphasizes “doing things right”, then product development is about “doing the right things.”
China’s furniture companies are gradually losing their advantages in labor costs and procurement costs. Therefore, the enterprises should implement tool and technology upgrades and industrial upgrades in a timely manner, instead of just emphasizing the number of new products developed and simplifying the development process, simply hoping to meet the diverse needs of the market with the number of products. Otherwise, it will fall into a vicious circle: the more companies give, the more the market will demand, and the more difficult it will be to satisfy.
However, under the cost-oriented design concept, the product development and management personnel of the enterprise will use standardized and modular ideas in the early stage of research and development. So that they can intervene in the consideration of product cost earlier, spend more time, and use advanced computer-aided design tools. Then, carefully comparing the differences between different design schemes, especially where it will have potential impact on subsequent mass production. That will greatly improve the quality of product development and the success rate of product development.
Enterprises will change from the operation mode of catering to the market with a large number of products to leading the market with high-quality products.
“If you miss a tiny bit, you will miss a thousand miles.” The author hopes that from a product design case described in this article, readers can see the huge impact of the early design of the product on the cost. And then think about the current upgrading of China’s manufacturing industry. In the context of intelligent manufacturing, in the development of traditional furniture products, think about what should we learn from the experience of advanced manufacturing. Next, use advanced tools, transform the development process, and manage new product development in a more “lean” way.
Article source: Furniture Today