According to Schilder, mechanical objective of cleaning and shaping is/are:
Schilder’s Mechanical Objectives of Cleaning and Shaping:

The root canal preparation should develop a continuously tapering cone.
Making the preparation in multiple planes which introduces the concept of “flow”.
Making the canal narrower apically and widest coronally.
Avoid transportation of the foramen.
Keep the apical opening as small as possible.
Canal should continuously taper
Canal should be prepared in multiple plane
Apical construction should be as small as possible
All of the above