Categorization of Characteristics | ||
Standard (Non-key) characteristics | Special characteristics (or Key characteristics / Significant Characteristics) |
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Function relevant characteristics (or Significant Characteristics) | Safety relevant / Governmental regulated characteristics (or Critical characteristics) | |
A product or process characteristic, that does not affect a product’s function, safety or compliance with governmental regulations.
No, or very minor impact on customer satisfaction. Low risk |
The variation of this characteristic significantly affect fit, form, function, performance or subsequent processing.
High impact on customer satisfaction! Moderate / High risk |
The variation of this characteristic significantly affects safety, or compliance with governmental regulations.
High impact on safety, environment, function or various governmental regulations! Non-conformance of characteristic may cause serious failure! Very high risk |
Example: Length of a USB stick. Even though the stick is longer, than specified in the drawing, it still works, and causes no functional failure. |
Example: Width of the USB stick’s port (terminal). In case the width of the terminal is not in specification range, the user cannot plug it into the slot. This causes functional failure (non-conformance of fit, form, function) |
Example: Pressure in the hydraulic break system. If the pressure is low, it causes the malfunction (functional issue) of the whole breaking system, and on top of that, it may risk injury (safety issue). |
Remark: many companies simply do not designate this category. | Remark: some companies use the phrase significant product characteristic, or key characteristics. | Remark: some companies call these critical characteristics. |
FMEA severity: 1 – 4 | FMEA severity: 5 – 8 | FMEA severity: 9 - 10 |