C.VEN/BA-M1/06

From HTMcommunityDB.org

Detailed Proof Table for this specific manufacturer-model (Brand A - Model 1) maintained at the manufacturer-recommended maintenance interval (6m)

Each individual segment of the Summary Proof Tables (Table 5) is provided with a "drill down" link that reveals the Detailed Proof Table shown below. This table shows a breakdown of the various batches of data (in this case four batches) that support the aggregated data shown in the Summary Proof Table. This example is using hypothetical data and is for illustrative purposes only. Please refer to the notes below the table for an explanation of the analysis used to derive the various parameters shown in the table.

This table was last updated on 7-14-17

• Back to Table 5.3HE Critical care ventilators (illustrative hypothetical example) (the Summary Proof Table), to Table 5, Table 1, The database Tables or the Main Page

Analysis

With respect to the experience base being considered acceptable. The reported total of 1492 device-years (line 6 column 6) is considered to be "Substantial" since it is >500 device-years. (Table 11).

With respect to this device being classified as device restoration-critical at LOS 3 (potential for life-threatening injury). Based on the reported total of 14 DR-related failures (line 6 column 10), the MTBF (mean time between failures) for this type of device, when maintained at a 6-month interval is 107 years (1492 device -years/ 14 failures), which makes its DR-related reliability/ safety Acceptable at the "good reliability" level (75-150 years). See Table 12

With respect to this device being classified as safety verification-critical at LOS 3 (potential for life-threatening injury). Based on the reported total of 6 SV-related failures (line 6 column 15), the MTBF (mean time between failures) for this type of device, when maintained at a 6-month interval is 249 years (1492 device -years/ 6 failures), which makes its SV-related reliability/ safety Acceptable at the "very good reliability" level (>150 years). See Table 12

Based on these findings - although potentially-critical this particular manufacturer-model should not be considered a PM Priority 1 device. In spite of the high level of the severity of the outcome if it fails (potentially life-threatening), its demonstrated good - very good level of reliability means that it should be considered a 'PM Priority 2 device. See Table 12

Table 5A Thresholds for acceptability of the size of the experience base (Copied from Table 11 - Still tentative)

Table 5B Definitions of the five different levels of device risk (copied from Table 12 - Still tentative)

The level of risk associated with a device failure caused by not completing the device's PM in a timely manner (which increases the risk that the device will fail) is determined by both the level of severity of the potential adverse outcome if the device fails (LOS 1, LOS 2, or LOS 3) and the device's demonstrated PM-related reliability (expressed as an MTBF* or mean time between failures).

So, devices that have at least one high severity failure mode (LOS 3) combined with a demonstrated poor PM-related reliability (MTBF less than 75 yrs) should be considered to represent the highest risk and labeled PM Priority 1 devices.

Devices with better levels of reliability (represented by longer MTBFs) and/or lower severity outcomes should be considered PM Priority 2, 3, 4 or 5 devices. The full hierarchy of different combinations of the worst-case severity of the result of the device failing and the device's demonstrated reliability is shown in the table below.

(This table was last updated on 4-9-16)

• For definitions of Outcome Severity Levels A thru H - see column 5 of Table 4

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