Outage planning on plant is notoriously difficult to predict, and even having predicted what plant is out when, it is almost impossible to assess what the effect on market price is. In theory outages should be done on a cost basis, when the plant is at its least profitable should be the time when the plant is taken out for scheduled maintenance. In reality this is difficult to do particularly when the engineers come from the same operators, who themselves are under pressure from a range of producers to provide their engineers all at the same time. Last year, the network had a series of NISM's (Notices of Insufficient margin) during August, because many plant took planned outages at the same time. Due to the nature of moving staff and the logistics of scheduling an outage, producers tend not to reschedule an outage to reflect price movements. At the moment quite a large proportion of plant is off line, and the problems of August 2004 look to be repeating themselves in June 2005. This is made worse by fuel prices and margins being as high as they are in that a badly scheduled outage is going to cost more. In reality the market has to bear the pain of a lack of supply at some time; whether this is August or June doesn't matter, it just means that the prompt can only get better when some of the plant returns to full generation having had its annual spruce up.