By defining a design space that the engineer has to work in and applying boundary conditions such as predefined loads and fixture positions, topology optimization can suggest the ideal layout of material to meet defined performance targets.
Freeform optimisation can be used at the concept level of the design process to arrive at a conceptual design proposal that is then fine tuned for performance, weight and manufacturability. This process replaces time consuming and costly design iterations and hence reduces design development time and overall cost while improving design performance.
It is important to note that design proposals from a freeform optimization study will present an optimal layout of material distribution which may be at odds with the manufacturing processes employed. As such there is still a need for the engineer to interpret the output from the study into a final manufacturable model that can be tested further. However, some new advances in manufacturing techniques such as additive layer manufacturing or 3D printing, has the potential for parts to closer resemble the freeform results.
Another problem is that the solution of a topology optimization problem can be mesh dependent, if no appropriate measure is taken.
Source: Altair Enlighten