I have a process A to B to C.  A to B represents Receipt of Customer
Order to Completion of Manufacture.  B to C represents Completion of
Manufacture to Delivery to Client.  My current problem is that the
clients are recieving their orders to EARLY.  This results in me
incurring storage charges as clients dont want their stuff too early. 
I am taking a policy decision that if clients recieve their stuff 2
days ealry, that's fine. We are never late in delivery. Therefore my
criteria is that my clients receive their stuff in Zero (on time) to
minus 2 (two days early).

We make thousands of products on varuous cycle times.  I am not
measuring cycle times.  I am trying to get a handle on our abiltiy to
predict / meet target delivery dates.

I know that in process A to B my performance is that 83% of our stuff
is manufactured to a "Zero  to -2".  Can you tell me what performance
I must achieve in process B to C to ensure that my overall performance
(A to C as seen in my customers eyes) is 80%.

Thanks