Large systems are typically acquired in defined phases separated by milestone events. Collectively, the phases and milestone events are referred to as:

A$.$

the product design engineering path

B$.$

the design evolution and test stages $($DETS$)$

C$.$

the sequence of activities path $($SAP$)$

D$.$

the systems acquisition process $($SAP$),$ which is also referred to as the Life Cycle Acquisition Process