Variant Configuration Options

We have a rather complex assembly that will be defined using variant configuration.

Thus far, we have two options for defining the item - using a single part number with class 300 characteristics or creating a unique part number for every conceivable combination of characteristics. This latter solution could entail as many as 4,000 part numbers.

The problems we're seeing have to do more with schedule instability. The variant configuration item is unique to the sales order and the customers have a tendency to change their schedule, even inside lead time. So these unique assemblies are difficult to identify using a single part number strategy, especially if they have to be held in stock for any period of time.

We would prefer to bring these in as just in time items, but the schedule instability will still make that a difficult effort.

What other possibilities do we have for configuring this item that will make it more readily identifiable without going to the unique part number soliution? Is there something in between one part number and 4,000?