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Critical care ventilator/ Carefashion-Velour/ 6 months

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Contents

Detailed Proof Table for this specific manufacturer-model (Carefashion-Velour) maintained at this particular maintenance interval (6m)

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

(This table was last updated on 1-15-16)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Data aggregator/ provider ID code Facility code Data
batch #
Sample size
(# of
devs) (N)
Time period in months (T) Experience base
(# of
device-yrs) (E)
Is size of experience base acceptable? # of
MR 1 failures

(M)
# of PM Code 9 failures

(W)
Total # of DR-related failures (M+W=)
(R)
MTBF
for
DR-related reliability
(E/R)
Level of
Severity of
DR-related
failure modes
Is level of DR-related reliability
/safety acceptable?
Device risk level (DR) # of (PM
Code F)
SV-related
failures
(S)
MTBF
for
SV-related reliability
(E/S)
Level of
Severity of
SV-related
failure modes
Is level of SV-related reliability
/safety acceptable?
Device risk level (ST)
System S1 F45 C.VEN/C1-V1/ 06/ B1 40 24 m
=
2.0 yrs
80.0
dev-yrs
Yes
50-200 dev-yrs
=
Good
0 1 1 80
years
LOS 3
(Life-
threatening)
Yes
75-150 yrs
=
Good
reliability
2 40
years
LOS 3
(Life-
threatening)
No
<75 yrs
=
Poor
reliability
Facility F2 F2 C.VEN/C1-V1/ 06/ B2 12 12 m
=
1.0 yrs
12.0
dev-yrs
No
<50
dev-yrs
=
Inadequate
0 1 1 12
years
LOS 3
(Life-
threatening)
No
<75 yrs
=
Poor
reliability
0 Undeter
-mined
LOS 3
(Life-
threatening)
Unknown
ISO Contractor
C1
F21 C.VEN/C1-V1/ 06/ B23 100 48 m
=
4.0 yrs
400.0
dev-yrs
Yes
200-500
dev-yrs
=
Very good
2 2 4 100
years
LOS 3
(Life-
threatening)
Yes
75-150 yrs
=
Good
reliability
1 400
years
LOS 3
(Life-
threatening)
Yes
>150 yrs
=
Very good
reliability
CMMS
Vendor
V1
F17 C.VEN/C1-V1/ 06/ B12 500 24 m
=
2.0 yrs
1000.0
dev-yrs
Yes
>500
dev-yrs
=
Substantial
2 6 8 125
years
LOS 3
(Life-
threatening)
Yes
75-150 yrs
=
Good
reliability
3 333
years
LOS 3
(Life-
threatening)
Yes
>150 yrs
=
Very good
reliability
Aggregated data for this man-model at this interval All
sources
C.VEN/C1-V1/ 06 652 2.3 yrs

(TWA*
= E/N)
1492
dev-yrs
Yes
>500
dev-yrs
=
Substantial
4 10 14 107
years
LOS 3
(Life-
threatening)
Yes
75-150 yrs
=
Good
reliability
PM
Piority
2*
6 249
years
LOS 3
(Life-
threatening)
Yes
>150 yrs
=
Very good
reliability
PM
Priority
3

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. (See Table 5A below).

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 5B below.

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 5B below.

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 3 device. See Table 5B below.

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


Experience base thresholds
(tentative)
Amount of data
(device-yrs)
Inadequate <50
Good 50-200
Very good 200-500
Substantial >500



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


LOS 3
(Life-
threatening
injury)
LOS 2
(Possible
patient
injury)
LOS 1
(Disruption
of patient
care)
PM
Priority 1
device
Poor
reliability
(MTBF <75 yrs)
Poor
reliability
(MTBF <50 yrs)
PM
Priority 2
device
Good
reliability
(MTBF 75-150 yrs)
Good
reliability
(MTBF 50-100 yrs)
Poor
reliability
(MTBF <25 yrs)
PM
Priority 3
device
Very good
reliability
(MTBF >150 yrs)
Very good
reliability
(MTBF >100 yrs)
Good
reliability
(MTBF 25-50 yrs)
PM
Priority 4
device
Very good
reliability
(MTBF >50 yrs)


The level of risk associated with a device failing caused by not completing the PM of a device in a timely and competent manner (which increases the risk that the device will fail) is determined by both the level of severity of the possible adverse outcome of the device failing and the device's demonstrated reliability (the demonstrated probability of the device failing).

So a device that has at least one high severity failure mode (LOS 3 or LOS 2) combined with a demonstrated poor reliability (MTBF less than 75 yrs for LOS 3, or 50 yrs for LOS 2) should be considered a PM Priority 1 device. Even with a demonstrated poor reliability (MTBF less than 25 yrs) a device that has only low severity failure modes (LOS 1) should be considered a PM Priority 2 device

Devices with better levels of reliability (represented by longer MTBFs) and/or lower severity outcomes should be considered PM Priority 2, 3 or 4 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 Table 5B above.


Abbreviations
DR Device restoration, as in the device restoration-related tasks listed in a device's recommended PM procedure.
SV Safety verification, as in the safety verification-related tasks listed in a device's recommended PM procedure.
Level of Severity (LOS) 1 A device whose failure could be life-threatening i.e. that could cause the patient (or the user) to lose his or her life.
Level of Severity (LOS) 2 A device whose failure could cause a patient injury.
Level of Severity (LOS) 3 A device whose failure could cause a disruption of care, such as, delaying treatment or diagnosis, or requiring one or more patients to be rescheduled.
MTBF Mean Time Between Failures - is the inverse of the device's failure rate. For example, a device that failed twice in nine years has an MTPF of 4.5 years.

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