Other ways that we classify products in order to satisfy customer demand is as follows:
Available–from-Stock Product
Certain products may be kept in stock on purpose due to frequency of demand, even though this may be random. If the product is in stock and has not been promised or allocated to another customer then delivery can be promised from this.
Assemble-to-Order Product
Quite often organisations may decide to assemble standard components or sub-assemblies when an order is received for them. An automotive company would complete this so that the customer gets the colour and specification that they require for their car. Dell are also one of the main examples of this in that you can order on-line from a key specification and your computer will then be assembled to your requirements. The main issue with this is that you need to have extremely responsive suppliers or else you may end up holding a large value of stock.
Make-to-Order Product
This is where a product is assembled to a customer unique specification, from components which are specially purchased for this requirement. Delivery date can only be promised when the organisation has sufficient capacity and agreements made for lead-times for supplies etc. in order to commit to one.