Recommended or Required Add on Sale Items

I my business as well as many that I know of, it is often necessary to sell items that have required accessories that are sold separately. 

MANY businesses have the need to prompt for NON-Required ADD ON sales.

For ONE Example, an item that is generic in application but can not be utilized as is and REQUIRES additional parts to make it work in various applications. In our case an item that can work with Chevy Tahoe, Ford Expedition and all the Full Size Pickups, but MUST be sold WITH an installation kit to fit the specific vehicle. So in our our software we coded those installation kits into a register much like the BOM register but when we entered the base item it popped up the list of required accessories to choose from. it would be perfecty suitable to get a RED BLOCK NOTICE that there are required items that need to be selected and just go to a required add on menu. 

For Second Example. Basically the same except the items are only recommended as add on sales either for convenience for the customer or enhanced roduct experience. Again, ideal would be a pop up list but a Colored Block Notice and a menu list would be acceptable

To accomplish both with the same list our old software simple had us mark where the list was required or recommended. and it was possible to have both lists on one item. It would not proceed unless an item from teh required list was selected. We had a “null selection” item that simply said “NOT REQUIRED” if the customer alread had the encessary parts. 

I would say +50% of sales organizations selling hard good of any technical nature will need this. it's really as simple as offering the customer batteries to go eitht eh flashlight (torch) they are buying.