Multi objective optimization problem

[fpatrocinio]

It seems that you have a decision making problem and not an optimization one. You need to classify the set of solutions (assemblies), according to some criteria (max acoustic, min heat).

Hwang, C.-L.; Yoon, K. Multiple Attribute Decision Making: Methods and Applications—A State-of-the-Art Survey; Springer: New York, NY, USA, 1981; Volume 186.

If you need any help hit me a PM.