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Contents 1 Executive Summary 2 Stakeholders and Stakeholder needs 3 Product Function 4 Assembly Components 5 DFMA Analysis 6 FMEA Analysis 7 DFE Analysis 8 Mechanical Analysis 9 References 10 Team Members

Executive Summary

Stakeholders and Stakeholder needs

Suppliers

Company Owner

Customers/Public

Product Function

Assembly Components

Part Number	Name	Qty.	Weight	Function	Material	Maunfacturing Process	Image
001	Plastic Casing	1	224g	Seperates the internal heating mechanisms from the user.	Polypropylene (PP)	Injection Molded
002	Crumb Tray	1	36g	Collects bread crumbs.	Aluminum	Stamp
003	Crumb Tray Handle	1	10 g	Handle to pull out crumb tray.	Plastic	Injection Molded
004	Toaster Loader Top	1	62g	Bread is loaded through slots.	Stainless Steel	Stamping, Deep Drawing
005	Toaster Base	1	108g	Base of toaster.	Polypropylene (PP)	Injection Molding
006	Regulator Knob	1	2g	Adjusts Toast time.	Polypropylene (PP)	Injection Molding
007	Press handle	1	8g	Easy surface to press, to lower bread into toaster.	Polypropylene (PP)	Injection Molded
008	Cancel button	1	2g	Cancels toast process	Polypropylene (PP)	Injection Molded
009	Power Cord	1	12g	Used to power toaster	Rubber and Copper	Extrusion
010	Ejection Assembly: Shaft	1	12g	Guide rail for ejection assembly	Steel	Extrusion
011	Handle and Locking Part 1	1	18g	Assists in triggering toasting.	Steel	Stamped and Bent
012	Handle and Locking Part 2	6	20g	Assists in triggering toasting.	Aluminum	Stamped
013	Toast Shelf	2	10g	Holds toast in place	Aluminum	Bent
014	Mystery Spring	1	1g	Used as a spacer, preventing ejection assembly from moving beyond a certain distance.	Steel	Extrusion
015	Restoring Spring	1	4g	Restoring Spring	Steel	Extrusion
016	Magnetic Lock Piece	1	8g	Attracts to magnet to lock the toasting shelf.	Steel	Stamped and Bent
017	Insulating caps for locking mechanism.	2	2g	N/A	ABS	Injection Molding
018	Shaft Spacer	1	2g	Spacer	ABS	Extrusion
019	Trigger Switch	1	2g	Triggers switch that activates the heating coils.	ABS	Injection Molding

DFMA Analysis

FMEA Analysis

DFE Analysis

Putting a slice of bread in the toaster, one does not often think about the environmental implications this act may have: “What steps were taken to enable this toaster to arrive on my countertop, how much power is it using while toasting, and what will happen to it after it I throw it away?” Delving into the life cycle of a toaster, we see that there is much room for improvement.

The key element in the life cycle of this appliance is energy. Being made of nearly completely recyclable materials, we are not focusing on the post-use phase. In both the production and use phases of a toaster, power generation and supply is the overwhelming contributor of greenhouse gas emissions. This seems fairly straightforward for the use end – in use, toasters produce little more than heat, from electrical power, and (hopefully) golden brown toast – but this may come as a surprise for the manufacturing end. Indeed, power generation and supply produces nearly four times as much CO2-equivalent than the nearest sectors, truck transportation and steel mills, during the manufacturing of such appliances.

Using the EIO-LCA software from Carnegie Mellon University’s Green Design Institute, we see that every $1,000,000 of production in the ‘Electric housewares and household fans’ sector produces 611 MTCO2E. Given our $10 toaster, this shows us that approximately 0.006 MTCO2E caused by the manufacturing of one toaster. To compare that to the use end, a simple calculation is done:

From the EIO-LCA, we see that for every $1,000,000 of production in the ‘Power generation and supply’ sector, 9910 MTCO2E are emitted.

Assuming: $0.10/kWh electricity cost, power consumption is 800W, usage is 6 min (0.1hr) per day, used 300 days out of the year, over the course of a 4 year use-life. We see that it would cost approximately $9.60 to run this toaster over the course of its life. Given this information, it is seen that the use phase of a toaster’s life emits approximately 0.095 MTCO2E. This is an entire order of magnitude higher than the emissions production phase. Clearly, one of our assumptions, above, needs to be modified. The only option which may not impact the functionality and longevity of the toaster is the power consumption.

The results for conventional air pollutants, such as SO2, NOx, and CO, show the same result: power generation, both for the creation and use of a toaster, is the largest contributor to harmful emissions.

Furthermore, looking at other toasters, we see that this 800W usage is on the low end of the spectrum. All residential toasters use the same heating method – running current through a filament, which generates heat. Perhaps a thorough rethinking of the method used to toast the bread is necessary.

The numerical results of GHG emissions, above, come with a good level of confidence. Though there are many sub-sectors of the ‘Electric housewares and household fans’ segment, the ‘Small electric household cooking appliances’ sub-sector represents nearly 1/3 of the overall sector.

Mechanical Analysis

References

Degentesh, Drew. "Metal Processing." 24-443: Design for Manufacture. Carnegie Mellon University. 11 Sept. 2008.

Degentesh, Drew. "Injection Molding." 24-443: Design for Manufacture. Carnegie Mellon University. 4 Sept. 2008.

Degentesh, Drew. "Plastics Processing." 24-443: Design for Manufacture. Carnegie Mellon University. 2 Sept. 2008.

DFM Textbook (will be updated)

Team Members

Leigh Fortenberry	Jon Goettler	Akshay Jayaram	Ian Price
Worked on DFMA, usability study, Stakeholder's needs	Worked on FMEA, Mechanical Analysis, analysis of timing system	Worked on Component List, Executive Summary	Worked on DFE, Product and System Function