I have "set" of product which consists of 7 pieces. 1 of each piece so only 1 set. Pieces can be sold individually so when a piece is sold, the inventory for the "set" should be 0. Likewise, if the "set" is sold, inventory for the 7 pieces should be zero. How can this be configured?
Sounds like you're looking for a bundled product. You can find more more about that here. Basically a bundled product is composed of simple products. It has no stock of it's own and depends on the stock of the simple products.