A top-down approach (also known as stepwise design and in some cases used as a synonym of decomposition) is essentially the breaking down of a system to gain insight into its compositional sub-systems in a reverse engineering fashion.
En top-down tilgang (også kendt som en et gradvist design og i nogle tilfælde benyttet som synonym for nedbrydning) er essentiel for at kunne nedbryde et system og opnå indsigt i dets sammenhængende undersystemer.