First Edition Dated September, 2000 43
At a minimum, suppliers need to be able to demonstrate the correlation
between the given requirements and the upper level design characteristics.
The interpretation and flowdown of requirements should be presented to the
customer for agreement prior to proceeding with the detailed design. World
class suppliers will seek to remove barriers and work in a collaborative
environment with their customers. The expected benefits are an improved
understanding of the customer’s requirements and measurable improvement
in the cost and quality of the overall product and process design.
Section 4.5.3 The design (drawing tree) shall account for all
stages of the fabrication and assembly process (build tree).
In order for the design to be robust to manufacturing realities, the drawing
tree shall reflect all stages of fabrication, assembly and functional testing
defined in the build process (build tree). Following this methodology ensures
that all customer requirements and key characteristics (see 4.5.2) can be
adequately flowed down through the complete product and process definition.
The methodology also results in datums and tolerances (see 4.5.4) that can
be documented for manufacturing, measurement and inspection. Finally,
defining each stage of the fabrication and assembly process supports the
generation of proper manufacturing instructions and minimizes the variation in
the outcome of the process.
1
2 2
1 1 1 1
=
Flow down
Flow down
Drawing Tree
Build Tree
Product Definition
1) Engineering drawings/datasets
2) Reference drawing required if no drawing
... .reflects a build position configuration
4.5.3_1
In the cases where it is not possible to have a drawing (or dataset) that
matches each element of the build tree (build position), a reference drawing
should be prepared to collect all the parts of that build position. This
reference drawing should include functional datums, tolerances, and testing
requirements (see 4.5.4 and 4.5.5). In larger projects, data may need to be
collected from several design groups. If both structural and systems
