I have found that in working situations 失礼しますが is always a good way to interupt someone while they are in the middle of something.
if someone is eating you can always say すみません食事中のに よろしいですか。
I think a simple ちょっといいですか (chotto ii desu ka), or XX さん、今、時間大丈夫ですか (XX-san, ima, jikan daijoubu desu ka?) is fine for many situations. In general, the workplace is an informal situation when dealing with colleagues. Superiors are a different matter, and would call for honorifics and other bells and whistles.
I think that this entry should be categorized "social" instead of "grammar".
I think it would be a good idea to add the hiragana(じゃま) or romanji(jama) of this kanji to the explanation. Most people who get as far as this page would know the pronounciation but.....