The INCOSE Certification Program's knowledge requirement has been the same since the program's start: knowledge of systems engineering processes and terms as described in the INCOSE SE Handbook. The validation methods for this requirement have also held steady, with draft exam questions tested on large, diverse groups of candidates. The verification methods for this requirement, however, have changed over time.

The initial verification method for the knowledge requirement is the INCOSE knowledge exam, offered in computer test centers worldwide. In 2014, the Certification Program began widespread offerings of the knowledge exam through pencil-and-paper in classrooms and conference rooms at INCOSE events. In 2020, INCOSE began offering the knowledge exam online with a remote, video proctor. As of 2022, the two ways to take the INCOSE knowledge exam are online from a personal location with a remote, video proctor and in-person using pencil and paper at an INCOSE event with an INCOSE-approved proctor in the room.

In 2013, INCOSE began forming relationships with other providers to recognize their knowledge assessments as equivalent or better than the knowledge exam. The first equivalency was within the German SE Zert. This led the way to verification through assessments other than multiple-choice tests and to assessment in language other than English. The Academic Equivalency Program that began in 2018 formalized allowing both of these differences from the INCOSE knowledge exam. Academic Equivalency (AcEq) is for universities that assess systems engineering knowledge, using the INCOSE SE Handbook, and it does not restrict the methods of assessment or the language used. The INCOSE Certification Program is actively searching for universities whose assessments or students differ from the traditional INCOSE SEPs, to reach a broader audience and ensure the path to INCOSE Certification is equitable.