The method of dividing the project scope into many parts that, when combined, would constitute the project deliverable is called :

decomposition

Explanation:

This is a technique used to divide and subdivide the scope of the project and the future to deliver, in smaller and more manageable parts. It is defined what work is going to be done and which is not. It is a hierarchical decomposition oriented to the deliverable product of work and achieve the objectives of the project.

answer; (cognitive   dissonance);

answer; allows decision to stand;