Development Dimensions International


Development Dimensions International is an international human resources and leadership development consultancy. DDI works with organizations to make changes related to leadership development, leadership selection, succession management, and execution and performance.
The company is headquartered in Pittsburgh, Pennsylvania and has more than 1,100 employees throughout 42 offices in 26 countries. William C. Byham, Ph.D., is chairman, Tacy M. Byham, Ph.D., is CEO, and David Tessmann-Keys is president.

Company Overview

DDI was founded in 1970 by William C. Byham, Ph.D., and Douglas Bray, Ph.D. DDI introduced the assessment center approach for identifying leadership skills. Byham’s article, Assessment Centers for Spotting Future Managers,'' led to inquiries about the process, and later, Byham approached Bray about a partnership.
DDI later branched out into leadership development. It introduced a leadership development program based on behavior modeling: Interaction Management. DDI next created a stand-alone behavioral interviewing system, Targeted Selection, which ensures compliance with Equal Employment Opportunity laws.
DDI’s also works on new HR technology, methodology, and content, including mid- and senior-level development, online assessment for frontline and mid-level leaders, and best practices for succession management.

Selected publications