Many internal and external performance consultants or vendors and academics who provide PT services have become CPTs. Internal consultants work within their organizations to implement PT in a collaborative systemic, systematic manner, focused on results. Vendors or external performance consultants use PT to provide another pair of skillful "eyes," bringing experience with different clients , different cultures, and different successes. The CPT website, www.certifiedpt.org, has the most current list of professionals who hold the CPT credential.