Boeing 81205 Manual

A SERVICE OF

next previous

First Edition Dated September, 2000 47

economically achieve them. If requirements cannot be economically met, then

a new manufacturing plan or a new design is required. Take, for example, the

tree in the figure below.

Drawing / Build Tree

Assembly ABC

Key

A

Key

A

Key

A

Part A

Part B

Part C

Key

Part B

Part C

A

Part A

4.5.5_0

The key characteristic at the top carries a ±0.03 tolerance on it. In order to

achieve this requirement efficiently at the assembly level, the requirement and

the associated tolerance must be flowed down and allocated to the detail part

characteristics correctly. But there are many manufacturing concepts that

potentially could be used to meet the assembly requirement. The figures

below depict different manufacturing concepts and how the tolerances might

be allocated to meet this assembly requirement.