PLS CITE URL OR REFERENCES USED: Under certain circumstances I can see extending the delivery period but if it causes additional work and cost for

PLS CITE URL OR REFERENCES USED: Under certain circumstances I can see extending the delivery period but if it causes additional work and cost for the vendor who should be absorb the expense? Delivery expectations are established for a reason because the client may have an important task to complete by a deadline which may create additional problems by extending the deadline. Who should be ultimately responsible for delays? Pls answer in 130 words or less.

Delivery delays have to be justified by the vendor and it is his responsibility to see that delaysare justified by whatever be the reason for the delay. It is also true that delays add more cost...