  The strategy used to develop the NIF Integrated Computer Control System
(ICCS) calls for incremental cycles of construction and formal test to deliver
a total of 1 million lines of code. Each incremental release takes four to six
months to implement specific functionality and culminates when offline tests
conducted in the ICCS Integration and Test Facility verify functional,
performance, and interface requirements. Tests are then repeated on line to
confirm integrated operation in dedicated laser laboratories or ultimately in
the NIF. Test incidents along with other change requests are recorded and
tracked to closure by the software change control board (SCCB). Annual
independent audits advise management on software process improvements.
Extensive experience has been gained by integrating controls in the prototype
laser preamplifier laboratory. The control system installed in the preamplifier
lab contains five of the ten planned supervisory subsystems and seven of
sixteen planned front-end processors (FEPs). Beam alignment, timing, diagnosis
and laser pulse amplification up to 20 joules was tested through an automated
series of shots. Other laboratories have provided integrated testing of six
additional FEPs. Process measurements including earned-value, product size, and
defect densities provide software project controls and generate confidence that
the control system will be successfully deployed.
