(S-90) (a) Each undefinitized change order  shall include a not-to-exceed price unless the CCO waives this requirement.

(b) The policies and procedures of DFARS 217.74  shall be applied to change orders (except value engineering change proposals (VECPs)) to  the maximum extent practicable.

(c) The use of VECPs are encouraged due to the  potential savings and system improvements that may be realized.

(1) Prompt action shall be taken to implement  those VECPs deemed to be technically sound.

(2) When considering VECPs, contracting officers  shall consider the impact on the projected savings that the normal negotiation and  definitization process would have versus use of an unpriced change order. Unpriced  contract modifications that implement VECPs shall:

(i) Define minimum unit cost savings, and

(ii) Define maximum development/implementation  costs