Which of the Following Is Not True About Value Analysis

Which of the following is not true about value analysis?

A) It involves an examination of the function of purchased parts or products.
B) Its purpose is to reduce costs and/or improve performance of purchased goods or services.
C) It is usually performed only periodically.
D) Representatives from design and operations may work with purchasing.
E) If improvements are identified,purchasing usually has the authority to implement them.