I think, there is a problem - thread interruption - when somebody is absorbed in his problem, and suddenly he is drawn away. May be he was diverted just for 5 minutes, but this is enough - man loses thought and it takes much more time to collect his thoughts again, very often more than 5 minutes. He was pulled out from the thread.
If it occurs once a day, it's may be ok, but if he is important enough, it may occurs 5-10 times. Calculate the loss.
I havn't found any effective solution of this problem. But I tried several methods:
Help request via e-mail. It hadn't justify hopes. Extracts from the reports:
“Help request via e-mail, taking into account the speed of message delivery etc., was "failed", so I want to forget about it.”
“Personally, it's inconveniently for me, it's simpler when smb asks for help via Skype/ICQ with the message a-la «If you will have a minute, please, come to me" - requests of such type, properly speaking, came in the team.”
"I'm busy marks" exposure. All who is busy should exposure a special mark, for example - red serviette or something else. Was met by laugh and pessimism.
Nevertheless, all team members admitted that the problem exists, but solutions remain the old - to ICQ or Skype someone for help with the messages like "Whistle when you'll be free" or to say "Sorry, I'm busy" when somebody tries to disturb you.