This study shows that top-down decomposition is problematic in the early stages of design. Instead, an opportunistic decomposition is better suited to handle the ill-structuredness of design problems. Designers are observed interleaving decisions at various levels of abstraction in the solution decomposition. The verbal protocols of three professionals designing a software system of realistic c...

The concept of a partial derangement is introduced and a versatile representation of partial derangements is proposed with permutations and derangements as special cases. The representation is derived from a representation of permutations by iterative decomposition of symmetric permutation group Sn into cosets. New algorithms are proposed for generation of partial set derangements in t. The con...