**11. Product architecture comparison and structural complexity**

The three architectures discussed display inherent differences in terms of density and connectivity. This is probably due to the existing architecture having a higher integration of the geared components, packed inside small-scale housing. As a result, structural complexity rises, and can be validated by computed metrics. The structural complexity and modularity metrics were calculated together with interconnections to show variations in their architectural properties. The formula for structural complexity is defined in the following as (**Figure 14**):

Structural complexity distinguishes the system architecture (scheme of interactions), determined by the form. Complexity of the individual components is composed by the total number of α's, to the addition with contribution of complexity due to the number of component interactions and their order. The second term is the

*Electrification for Aero-Engines: A Case Study of Modularization in New Product… DOI: http://dx.doi.org/10.5772/intechopen.109006*

**Table 2.** *DSM of old architecture [17].*

increased outcome of the total number of interfaces and graph energy. Component complexities are evaluated and exhibit the internal complexity of individual components in the structure (**Figure 15**) (**Table 5**).

#### **Table 4.** *DSM of new architecture.*

The DSM for the new architecture shows significantly more connectivity in all areas measured, with a 19% increase in connection density of the DSM. The individual connection types all decreased in number, indicating a less inter-connected

*Electrification for Aero-Engines: A Case Study of Modularization in New Product… DOI: http://dx.doi.org/10.5772/intechopen.109006*


**Table 5.** *Comparisonof*

 *all three* 

*architectures.*

#### **Figure 15.**

*Main dimensions of complexity in product development [19].*

#### **Figure 16.**

*Complexity-modularity: Impact and effectiveness [20].*

architecture. The largest increase, 30%, is found for the information. This lower level of interconnectivity deduces that the electric engine is significantly more "modular", and this is evident in the high modularity (Q) index.

The increase in graph energy E(A), show that the electric system is more distributed than the geared architecture in the table. The modularity analysis demonstrated for the different engine architectures (total connectivity) of the matrix reveal many inherent modules. The electric architecture is significantly less complex.

**Figure 15** represents ideal quadrants and its effective zones (low complexity, high modularity) where strategies work well using decomposition techniques to tackle system design and development (**Figure 16**).
