Down Time

The down time statistics are based on individual fault reports. In Table 1 I give the general down time statistics for period 38. A total of 88 fault reports were submitted, with an average time lost of 3 min per fault, for a total down time of 0.2% (0.2% on scheduled observing nights). Of these, 66 reported no time lost, 22 reported $<$ 2 hrs lost, and none reported 2 or more hrs lost.

Table 1: Technical down time statistic period 38: 2008-10-01 to 2009-04-01

Night included	Time lost	Nights	Percentage$^a$	Last semester	Last winter
All nights	250 min	182	0.2%	1.8%	0.8%
Scheduled observing nights$^b$	220 min	132	0.2%	0.1%	1.1%
Technical nights	30 min	23	0.2%	0.1%	0.4%
Service nights$^c$	35 min	27	0.2%	0.1%	1.1%
Visitor instruments	0 min	20	0.0%	6.8%	0.0%
$^a$ Taking the average length of time within nautical twilight. Exact numbers for each night
are used when looking at ``All nights''
$^b$ Excluding technical nights and visitor instruments
$^c$ Excluding service nights with SOFIN

The down time statistics are based on individual fault reports. In Table 1 I give the general down time statistics for period 38.

This compares to a down time of 1.8% over all nights (0.1% on scheduled observing nights) in period 37, and 0.8% over all nights (1.1% on scheduled observing nights) in period 36. Of the 95 fault reports reported in period 37, 63 reported no time lost, 28 reported $<$ 2 hrs lost, and 4 reported 2 or more hrs lost. Of the 74 fault report in period 36, 47 reported no time lost, 24 reported $<$ 2 hrs lost, and 3 reported 2 or more hrs lost.

The reported downtime is at an all time low, where it is clear that the main difference has been that no major problem occurred during period 38. The only `negative' side of being so close to zero is that the down time can really only go up...