  The Cherenkov Telescope Array (CTA) is a future instrument for
very-high-energy (VHE) gamma-ray astronomy that is expected to deliver an order
of magnitude improvement in sensitivity over existing instruments. In order to
meet the physics goals of CTA in a cost-effective way, Monte Carlo simulations
of the telescope array are used in its design. Specifically, we simulate large
arrays comprising numerous large-size, medium-size and small-size telescopes
whose configuration parameters are chosen based on current technical design
studies and understanding of the costs involved. Subset candidate arrays with
various layout configurations are then selected and evaluated in terms of key
performance parameters, such as the sensitivity. This is carried out using a
number of data analysis methods, some of which were developed within the field
and extended to CTA, while others were developed specifically for this purpose.
We outline some key results from recent studies that illustrate our approach to
the optimization of the CTA design.
