NX Nastran solves large systems of equations efficiently using sparse matrix algorithms however, the superelements capability offers still greater efficiency. Superelements, an add-on to Femap with NX Nastran base module, plays a key role when solving very large and complex finite element models by decomposing larger structures into equivalent sets of smaller substructures called superelements. Superelements can be used with all NX Nastran analysis capabilities. It is particularly efficient in large, full-system analysis such as for an entire aircraft, vehicle or ship, and performs incremental and partial assembly solutions