The evolution to computer-integrated manufacture (CIM) has been slower
than expected. This can be attributed directly to high software devel
opment and maintenance costs and the difficulty in achieving the requi
red levels of integration between systems. These problems are especial
ly evident in the development of the shop-floor control system (SFCS).
Many researchers have developed 'standard' CIM architectures. However
, these structures are often verbose, textual descriptions that are am
biguous and lack formality. This makes descriptions based on these arc
hitectures unsuitable as a basis for control software development. Fur
thermore, without a formal language for describing manufacturing syste
ms it is difficult for researchers to discuss and compare different sy
stem configurations. In view of these problems, this paper identifies
a formal structure for shop-floor control. The formal structure is bas
ed on a three-level hierarchical control architecture. The purpose of
this structure is to allow manufacturing systems to be described compl
etely and unambiguously. This description can then be used as a basis
for control software development, which will simplify the implementati
on of automated CIM systems.