We might consider whether a service supply chain extends beyond the customer supplier. Might the customer-supplier have a supplier? In some cases, the customer-supplier may be the originator of their own inputs. For example, phone company customers supplytheir ownvoices for processing.
In other cases, the customer-suppliers may have other suppliers. However, these are often difficult or impractical to co-ordinate with. One reason is thatevery customer-supplier may have a unique supplier. For example, various customers of a shoe repair shop may each bring shoes that were obtained from a different source. It is likely to be impractical for a shoe repair shop to implement any degree of co-ordination with those various shoe suppliers ± such asto standardizeshoe components.