"preparatory part" is a correct and usable phrase in written English.
You can use it when referring to the part of something that leads up to or prepares for the main part. For example, "The preparatory part of the discussion was devoted to addressing the members' questions about the meeting agenda."
Psychology is a preparatory part of philosophy, not a distinct science.
Section 2 is the preparatory part, Section 3 is the main part and Section 4 is the additional part of this paper.
The text that Tippett prepared follows the three-part structure used in Handel's Messiah, in which Part I is prophetic and preparatory, Part II narrative and epic, Part III meditative and metaphysical.
Mr. Zander conducted the Youth Philharmonic Orchestra, which is part of the conservatory's preparatory division, serving students ages 5 to 18.
Those who feel they lack the necessary basic technical education may take the preparatory EAS part 0 course before the test.
One of the lowest performing schools on the list this year was KIPP Impact Middle School, a college preparatory school part of the Knowledge is Power Program, a national network of open-enrollment schools in underprivileged communities.
The first part of the research project was of an exploratory and preparatory character.
Thirty-eight preparatory students took part in the study.
Locally appropriate bio-based packaging to promote sustainable food supply chains and green economies was a key objective advocated by an FAO Forestry body preparatory meeting as part of FAO's ongoing dialogue with the forestry private sector.
The second type of drawing, the preparatory study, is typically part of a progression of drawings that elaborate a design.
In this article the authors report results from a community-based closed cohort study, which is part of preparatory research for Phase III HIV vaccine efficacy trials being conducted by the Makerere University-Walter Reed Project in Uganda, a project sponsored by the US Military HIV Vaccine Research Program network.
