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Assembly Complexity Index Calculator

Design for Manufacturing and Assembly

DFA Design for Assembly Complexity Index Calculator

Cummins, Inc. engineering and manufacturer of Diesel engines and powertrains uses the following metric to determine an assemblies complexity index.

DFA Complexity Factor
Figure 1 - DFA Complexity Factor

DFA Complexity factor equals the square root of the sum of Np multiplied by the sum of Ni.

Eq. 1
DFC = ( Σ Np · Σ Ni )(1/2)


Np = Number of parts in assembly
Ni = Number of part-to-part interfaces

Smaller is better ( Minimize Np and Ni )

From figure 1

Np = 5
Ni = 8
DFC = 6.3



Kelly L. Bramble, ASEM S-GDTP. FAA A&P,
Engineers Edge, LLC