Table 2 Comparison of optimization methods, objectives, algorithm parameters, and characteristics.

From: An axiomatic system engineering design method based on NSGA-II algorithm applied to complex systems

Method

Optimization objective

Algorithm parameters

Characteristics

Traditional reduction algorithm

None

–

Performs strongly connected component decomposition followed by topological sorting. Deterministic approach without stochasticity, yielding a unique fixed ordering.

GA

Single objective: minimize UV

Population size = 100; 50 generations; crossover rate = 0.7; mutation rate = 0.3 (shuffle); selection: tournament

Outputs a single best solution based on evolutionary search.

NSGA-II

Multi-objective: minimize UV, maximize SD

Population size = 400; 350 generations; crossover rate = 0.7; mutation rate = 0.3; non-dominated sorting with crowding distance

Generates a Pareto front of trade-off solutions; three representative solutions are selected for analysis.

Evaluation metrics

UV (Upper-triangular dependencies); SD (Structural modularity score)

–

Used for visual comparison of DSM reordering and quantitative performance evaluation.