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...



Subsections
Thomas Augusteijn 2009-05-14