Assumptions:
1. All the components in a subsystem are
independently and identically distributed (iid)
2. Each component and the system may be one of
M+l states: 0, 1, 2, ..., M where 0 is the
complete failure state, M is the perfect working
state, and other states are the intermediate states.
3. The utility of the system when it is in state i is
represented by q. It represents the net profit or
loss the system can generate if it is in state i.