[PCI DSS 1.x] 6.4 Follow change control procedures for all system and software configuration changes. The procedur

6.4.a Obtain and examine company change-control procedures related to implementing security patches and software modifications, and verify that the procedures require items 6.4.1 – 6.4.4 below
6.4.b For a sample of system components, critical servers, and wireless access points, examine the three most recent changes/security patches for each system component, and trace those changes back to related change control documentation. Verify that, for each change examined, the following was documented according to the change control procedures: