Longer term overview

To give a longer term view of the kind of faults, and the amount of downtime as a function of the system and kind of fault, in Table 3 an overview is given for the past 22 semester (the period over which the data base is in use), from April 1, 2004 till April 1, 2015. Over this period, there were 2030 fault reports, reporting a total of 331.5 hr down time. Beyond the amount of time lost and the number of faults reported, also the percentage for each is indicated. These numbers give a good indication of the range and distribution of the kind of problems that are encountered and need to be resolved to maintain operations.

Table 3: Down-time statistics for periods 29-50$^a$

Syst/Type	Soft		Elec		Optics		Mech		Others		Total
Telescope	138	17:45	161	61:35	3	00:15	82	51:30	26	07:05	410	138:10
%	6.8	5.4	7.9	18.6	0.1	0.1	4.0	15.5	1.3	2.1	20.2	41.7
Building	3	00:00	49	08:25	1	00:00	45	01:45	16	00:00	114	10:10
%	0.1	0.0	2.4	2.5	0.0	0.0	2.2	0.5	0.8	0.0	5.6	3.1
Computers	267	17:49	43	06:50	0	$-$	3	00:00	35	02:50	348	27:29
%	13.2	5.4	2.1	2.1	0.0	0.0	0.1	0.0	1.7	0.9	17.1	8.3
ALFOSC	375	41:57	67	20:35	30	03:05	20	07:45	20	01:10	512	74:32
%	18.5	12.7	3.3	6.2	1.5	0.9	1.0	2.3	1.0	0.4	25.2	22.5
MOSCA	31	04:50	11	00:20	3	00:00	8	00:30	4	00:40	57	06:20
%	1.5	1.5	0.5	0.1	0.1	0.0	0.4	0.2	0.2	0.2	2.8	1.9
NOTCam	119	06:10	32	01:45	7	00:40	28	16:15	14	01:50	200	26:40
%	5.9	1.9	1.6	0.5	0.3	0.2	1.4	4.9	0.7	0.6	9.9	8.0
StanCam	59	07:45	2	00:30	2	00:00	14	00:10	12	02:05	89	10:30
%	2.9	2.3	0.1	1.5	0.1	0.0	0.7	0.1	0.6	0.6	4.4	3.2
FIES$^b$	115	18:10	37	06:35	1	00:00	6	00:40	7	00:55	166	26:20
%	5.7	5.5	1.8	2.0	0.0	0.0	0.3	0.2	0.3	0.3	8.2	7.9
Others	18	00:20	34	02:15	4	00:30	34	05:05	44	03:10	134	11:20
%	0.9	0.1	1.7	0.7	0.2	0.2	1.7	1.5	2.2	1.0	6.6	3.4
Total	1125	114:46	436	108:50	51	04:30	240	83:40	178	19:45	2030	331:31
%	55.4	34.6	21.5	32.8	2.5	1.4	11.8	25.2	8.8	6.0	100	100
$^a$ For each system-type category the total number of faults and total time lost is given. The
corresponding percentage compared to all faults are given in the second line
$^b$ FIES was commissioned in early 2006, and the first observing run was in October of that year, at
the start of period 34