Ski boot walking attachment

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Revision as of 18:38, 9 December 2008

Failure Mode and Effects Analysis (FMEA)

Design for X (DFX)

Design for X (DFX) analyzes a product to evaluate the efficiency of the product design from various perspectives. In this report, three major analyses are conducted on our final walking attachment design – Design for Manufacture (DFM), Design for Assembly (DFA), and Design for Environment (DFE). By conducting three types of DFX analyses, the overall efficiency of the product design during the manufacturing stage (DFM), assembly process (DFA), and post end-use impact to the environment (DFE) will be determined.

Design for Manufacture (DFM)

This design for manufacture analysis discusses how individual components of the walking attachment were designed in order to minimize the time and cost of the manufacturing process. The product design can be optimized for the manufacturing process through (1) reducing the number of components, (2) homogenizing the components, or (3) redesigning of the components. Reducing the number of components or homogenizing the components cuts the capital cost of production as fewer machines are required to manufacture the product. On the other hand, redesigning of the product aims to reduce the material cost per unit product by subtracting the unnecessary portions (dead weight) of the components from the original design. The following features of the final design contribute to the ease of manufacturing.

Symmetry

The walking attachment is identical for both the right and left boot. Because of this, the walking attachments can all be produced in the exact same way and they can simply be sold in pairs, without having to make sure there is one of each type in each pair. In addition to symmetry across the body, the walking attachment is, itself, symmetrical. If you cut the design down the middle from the front to back, it is a mirror image of itself. With this, the pieces of silicon and rubber on each side can be die stamped in the same way and that simplifies the manufacturing process.

Low Part Count

Because the final design contains very few parts, there are only a few manufacturing processes involved. We only need the rubber, silicon, and foam to be stamped, the entire top plate with toe piece can be made with two injection molding processes (one for the front and one for the rear), and the clip components, the links, and the folding rods can all be machined with relative ease. This is a pretty low number of manufacturing processes, and much of it can be done for a low price and in a small amount of time.

Easy Production

None of the processes listed above are incredibly time-consuming or costly and therefore manufacturing costs will remain relatively low. Each of the pieces production methods and advantages are listed below.

Top Plate

• The entire plate with toe piece can be made using injection molding allowing for a lightweight and robust design.
• Injection molding will waste little material and take a relatively low amount of time.
• Compared to other manufacturing processes, like machining, that could be used for this part, less material will be wasted, it will be faster, and at a higher production run, will cost less per unit.

Sole Components

• The sole components (the rubber, silicon, and foam) can all be die stamped.
• The production time will be very low.
• Although some material will be wasted, time saved and low input costs will keep the overall manufacturing costs low.

Clip Components

• The metal parts composing the clip can all be machined to specification with relative ease and little time.
• The metal pieces are all pretty simple, so machining will be easy and very few of them involve material removal.
• The plastic pieces on the clip can be made using injection molding.
• This allows for fast production and little material waste.

Design for Assembly (DFA)

A Design for Assembly analysis discusses how each component of the product was designed to minimize the time and cost of assembly. Efficient product design for assembly involves (1) simple configurations of the assembly and (2) ease of aligning the components. Simple configuration of the components prevents confusion and misplacement during the assembly process, while ease of aligning the components speeds up the assembly. The DFA on the main components of the walking attachment are provided below.

Sole

The sole is designed with a few pieces of rubber and foam embedded into two foam beds. All of these components are going to be die stamped, so the entirety of the assembly process will be arranging the pieces properly, and then gluing them together in the correct configuration. This must be done for the front and rear part of the sole. After these pieces are put together, the tread will be glued on to the bottom of the completed sole, and then the sole pieces themselves will be glued onto the front and rear top plates. Overall, the low number of parts and the simple arrangement were made for ease of assembly.

Top plate and Toe Piece

The top plate pieces themselves require no assembly since they each come as a single injection molded piece. In order to link the two halves together, the assembly worker must put the links in the appropriate slots, then slide the rods into the holes on the sides of the plate, and then simply cap the holes so the rod doesn't slide out. After that, the employee needs only to slide the rod through the rear plate, attach the clip to it, and then cap the ends. This linking design was made for very fast assembly because it only requires a few very easy steps.

Clip

The clip is by far the most complex part of the device for assembly. Although the assembly steps are somewhat difficult, there aren't that many parts so it doesn't take away from the overall low assembly time. The worker must take the large metal arc and rivet it to the connecting rod and then put the spring containment shell over the connecting rod. Once they put the spring inside, the cap needs to be attached to the end, and then the plastic clip itself needs to be screwed onto the metal arc. The clip is then completed and needs to be attached to the top plate to complete assembly of the device.

Design for Environment(DFE)

EIO-LCA

• Model used:
  
  • US Department of Commerce 1997 Purchase Price
    
  • Walking Attachment Price ~ $20
    
    
• Manufacturing Sector:
  
  • Industry Group: Misc. Manufacturing
    
  • Industry Sector: #339920 - Sporting and athletic goods manufacturing
    
• End-use Sector:
  
  • Industry Group: N/A - Negligible environmental impact from operations of the product
    
• Post End-use (product after life) Sector:
  
  • Industry Group: Management, Administrative, and Waste Services
    
  • Industry Sector: #562000 - Waste management and remediation services
    
    

Comments on the industry sector selections
The manufacturing sector of the walking attachment is best represented by "Sporting and athletic goods manufacturing" sector. The example of the industries included in the sector include but are not limited to manufacturing of ski boots and various plastic athletic equipments. Given that the product is made of rubber materials (commonly used in several athletic equipments) and that the product's primary operation is for athletic/leisure purposes, "Sporting and athletic goods manufacturing" sector best describes the manufacturers of ski boot walking attachment - a very unique product.

EIO-LCA result displaying conventional pollutants per every $1M of product

Manufacturing Sector: Conventional Pollutants per every $1M of Product Manufactured

Post End-usage Sector: Conventional pollutants per every $1M of Product Disposed

EIO-LCA result displaying GHG emission per every $1M of product

Manufacturing Sector: GHG emission per every $1M of Product Manufactured

Post End-usage Sector: GHG emission per every $1M of Product Disposed

EIO-LCA result displaying Toxic Release per every $1M of product

Manufacturing Sector: Toxic Release per every $1M of Product Manufactured

Post End-usage Sector: Toxic Release per every $1M of Product Disposed