This paper may be seen as an appeal to maintenance modellers to work w
ith maintenance engineers and managers on real problems. Such collabor
ation is essential if maintenance modelling is to be accepted within t
he engineering community. It is also particularly important in the des
ign and building of maintenance management information systems if such
systems are to be used to manage and operate maintenance policy in th
e new millennium. In this context, developing areas of maintenance mod
elling are discussed, namely: inspection maintenance; condition based
maintenance; maintenance for multi-component systems; and maintenance
management information systems. Some new models relating to capital re
placement are also considered. Thus, we are concerned with the mathema
tical modelling of maintenance rather than with management processes r
elating to maintenance. Discussion of maintenance management informati
on systems is included because of their importance in providing data f
or mathematical modelling and in implementing model-based maintenance
policy. (C) 1997 Elsevier Science B.V.