Setup planning is considered the most significant but also difficult activi
ty in Computer Aided Process Planning (CAPP), and has a strong impact on ma
nufacturability, product quality and production cost. Indeed, setup plannin
g activity deserves much attention in CAPP. The setup planning in manufactu
ring consists mainly of three steps, namely, setup generation, operation se
quence, and setup sequence. In this paper, the Kohonen self-organizing neur
al networks and Hopfield networks are adopted to solve such problems in set
up planning efficiently. Kohonen self-organizing neural networks are utiliz
ed, according to the nature of the different steps in setup planning, to ge
nerate setups in terms of the constraints of fixtures/jigs, approach direct
ions, feature precedence relationships, and tolerance relationships. The op
eration sequence problem and the setup sequence problem are mapped onto the
traveling salesman problem, and are solved by Hopfield neural networks. Th
is paper actually provides a complete research basis to solve the setup pla
nning problem in CAPP, and also develops the most efficient neural networks
based approaches to solve the setup planning problem in manufacturing. Ind
eed, the results of the proposed approaches work towards the optimal soluti
on to the intelligent setup planning in manufacturing.