Does your company use only ONE Probability table?

Medical device companies usually have more than one product. It is within the realm of possibility for a company to expand its device portfolio and market devices with different level of risks .

Should the risk management process in particular the probability of occurrence table change accordingly?

Consider the following real-life example: A medical device manufacturer produces an infusion pump, or hemodialysis machine, or any other type of capital equipment that requires a disposable kit in order to function as intended.

Considering the design complexity of an infusion pump, or hemodialysis machine. It would be reasonable to expect for the medical device manufacturer to be capable of producing thousands of units per year (1 to 9,999). In order for the device to function as intended, or in order to meet market demand. The same medical device manufacturer needs to produce tens of thousands (1 to 99,999) of the required disposable accessories or kits.

Now, few months later a customer complaints about a display on one of the infusion pumps not working. Later, another customer mentions there are 20 disposable kits with incorrect connectors. You can calculate the quantitative probability value of both display issue and incorrect connector.

Total number of infusion pumps: 2340

Number of complaints: 1

Calculated Probability P: 0.043%

Total number of disposable kits: 44,550

Number of complaints: 20

Calculated Probability P: 0.045%

Please determine what the qualitative P value would be in accordance to your company's risk procedure.

Just in case you are using only ONE probability table mentioned in the ISO standard then in both of these cases the converted qualitative P value would be 4! I hope you realize that realistically receiving only 1 complaint should not equate to P=4.

Instead of using the traditional methods, we can use the QQ CHART App to determine the correct probability value.

For the display issue the correct P value is 1.

For the connector issue the correct P value is 2.

Try it out for yourself, Download for Free the QQ CHART from Apple or Google Play Store.