We are evaluating moving off of Sage BusinessWorks (which handles accounting, order entry, inventory control, accounts receivable, etc) to Zoho Books/Inventory.

One of the things we heavily use is a feature called Kits, which allows creating a group of parts. When the kit is added to an order, it just adds the individual parts themselves to the order. This is preferred over composite items for a handful of reasons:

In Zoho, composite items is really better suited for assembled items. Sage BusinessWorks has a feature similar to composite items but they call it "Subassemblies". The use case is when you take parts from inventory to make a finished good. Using a table as an example, you may have individual items stocked for "table legs" and "table top", but you don't sell those items (they still need to exist in the inventory system though for tracking/accounting purposes). To sell a table, you have to build it first. So you take 4 legs and 1 table top out of inventory, then "build" the subassembly. It decreases the quantity of the individual items and increases the inventory of the table item. The packing list shows a single table, and the customer receives a single table.

Another example would be a home router. You would receive componentsfrom suppliers (plastic housing, circuit boards, etc) and adjust them in inventory. Then during the assembly phase, you'd build (bundle) those items, making a single router and removing the individual components from stock.

Attached you can see an example of how kits are set up, and how they are added to an order (it just inserts all the items into the order).