I often wonder how to interrupt people to ask them a question at work... ----
すみません、少しよろしいですか? might be short and polite enough.
One way to sound polite or reserved is try not to finish your sentence. It might sound weird but a half-finished sense can hand over the baton to your partner. For instance, ”すみません、質問があるんですが、、、。” It lets the partner take over the conversation, he may say, "何ですか?”then you can proceed saying, "質問があるんですけど”. Your sentence ”すみません、質問ありますので、少し時間いただけますか?"has no problem but it can be a too long sentence depending on the scene. In other words you might end up with holding your partner from speaking for too long. Your sentence might be better to finish halfway such as ”すみません、質問があるんですけど…” or finish it by combining all the elements, ”すみません、質問してもよろしいですか?”
dc
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。
tigert
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.
Eric
I think that this entry should be categorized "social" instead of "grammar".
赤毛
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.....