Customer Needs
The customer’s primary need is to cool a room by circulating air. More air circulation provides greater air movement and cooling potential. The fan’s noise level is a concern of the customer. Quiet operation, with little to no vibrations is preferred. The customer must also be able to adjust the fan’s rotational speed to best suit the surroundings. This allows for quieter, lower energy, operation when maximum air circulation is unnecessary. Another necessity is the ability to vary the direction of where air is being. This includes altering the vertical orientation as well as providing horizontal oscillation. The fan should also be safe for the user. This involves shielding the fan blades, while still allowing air to pass through. This shielding prevents objects and body parts from coming in contact with the blades. Fans are generally only used during warm times of the year. As a result they must be easy to move and store while not in use.
Item and Function | Failure Mode | Effects of Failure | S | Causes of Failure | O | Design Controls | D | RPN | Recommended Action | Responsibility and Deadline | Actions Taken | S | O | D | RPN
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Motor/Shaft
| Inhibited Rotation | Inefficient Operation | 5 | Debris (e.g. dust) in Fan | 4 | Run Under Extreme Dust and Debris Conditions | 2 | 40 | Filter, Accessibility for Cleaning, Better Protection of Rotating Parts | Motor Housing | - | 5 | 3 | 2 | 30
|
Swivel Mount
| Nut Stripping, Plastic Fracture | Cannot Adjust Vertical Directoin Fan Cannot Effectively Circulate Air | 8 | Overtightening, Material Failure | 3 | Overtightened Screw, Force applied on Swivel Area | 1 | 24 | Use Torque Limited Fastening, Using Stronger Plastic | Swivel | - | 8 | 2 | 1 | 16
|
Oscillation Button
| Dislocation of Button | Cannot Toggle Oscillation | 6 | Stripped Gear, Button Disengaged | 5 | Stronger Gears, Improved Connection | 2 | 60 | Fatigue Testing | Gears and Button | - | 6 | 3 | 2 | 36
|
Blade Cover
| Inhibited Rotation, Blade Fracture | Complete Inoperable | 8 | Penetration of Cover | 4 | Penetrate Repeatedly | 1 | 32 | Warning Label, Redesign Cover | User | - | 8 | 3 | 1 | 24
|
Shaft
| Non-concentric Rotation | Vibration and Noise | 5 | Broken Bearing, Unbalanced Weight, Shaft Non-Uniformity | 2 | Quality Control | 3 | 30 | Vibration Testing | Assembly | - | 5 | 1 | 3 | 15
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Electronics
| Short Circuit | Completely Inoperable | 8 | Exposure to Water | 3 | Water Exposure Testing | 2 | 48 | Waterproof Housing of Electronics | Housing | - | 8 | 1 | 2 | 16
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