Which of the following system and data conversion strategies provides the GREATEST redundancy?

A.
Direct cutover

B.
Pilot study

C.
Phased approach

D.
Parallel run

Explanation:
Parallel runs are the safest-though the most expensive-approach, because both the old and new systems are
run, thus incurring what might appear to be double costs. Direct cutover is actually quite risky, since it does not
provide for a ‘shake down period’ nor does it provide an easy fallback option. Both a pilot study and a phased
approach are performed incrementally, making rollback procedures difficult to execute.