Abstract
This study aims to develop a diagnostic tool that can measure nine personality types of the enneagram types based on the theoretical content of enneagram to measure personality as a human factor among various factors that affect to performance for maximizing organization and individual's performance. We have develeped measure items to figure out 9 enneagram types. Since first of September of to 30th August 2011, we had a preliminary survey with total 842 students in zed the data. Based on the results of the analysis of preliminary invmiddle and high school and analyestigation, we made a Enneagram Personality Type Inventory for Young People with a total of 144 selected questions. 4,008 middle and high students across the country were surveyed and had statistical analysis with the data. The data shows Cronbach's ${\alpha}$ was from .77 to .86 for the 9 types. This diagnostic tool developed with this study will help students can understand, develop and grow themselves, also this can be useful in coaching and counseling areas like Personality, career, academic, career and leadership development.