faff about – To waste time on an unproductive activity [wiktionary][urbandict]

Designing a new product is all about balancing trade-offs – how to get the best out of the limited budget. Someone propoosed to add a feature to the product, but was objected by another: “It looks nice but is not essential. I don’t think it is worth one month time faffing about how to implment it.” This phrase is mainly used in the British English (according to wiki). So if you say it to an American, you may get a puzzled look.