There are many good reasons to do yearly disaster recovery testing.
First and foremost, yearly disaster recovery testing can prove if a disaster recovery plan will work or not. If it does not work, issues are encountered, or gaps are found, disaster recovery tests become a great opportunity to make the changes needed to a disaster recovery plan to ensure it will be successful.
Disaster recovery tests also allow for those executing the test to come up to speed on any changes made to the disaster recovery plan in the last year.
While yearly disaster recovery testing is good, a more frequent DR testing basis is better. More frequent disaster recovery tests increase the rate of success by providing additional opportunities to verify disaster recovery plans, and fix any issues encountered.
In order to ensure disaster recovery plans can be tested frequently, a disaster recovery solution with automation is key. By automating the DR test process, tests become easier to run on a recurring basis.