Abstract:
Block replacement is a preventive maintenance policy where a large number of identical,
low cost operating components are replaced group-wise after certain time intervals. To
ensure availability of spare items when operating components are to be replaced after
breakdown or block replacement interVal, there is always a tendency to overstock the
components. Excess inventory of the components involves substantial capitaL In a
maintenance organization, normally, maintenance and spare parts provisioning are treated
as separate problems, with special attention to maintenance policy. Inventory .systems
matching stochastic demand pattern could also be designed and therefore combined
optimization of maintenance and inventory functions can be anticipated to prove more costeffective
than considering these policies separately. This general problem forms the basis of
the present research
In the present research a manufacturing system has been considered to solve the general
problem of optimizing joint maintenance and inventory policies. This system comprises of
several work centers and the focus is on the stochastic failures, replacements and order lead
times of a single type of statistically identical items, common to each of the work centers.
The system is highly complex to be described by a mathematical modeL A simulation model
has, therefore been developed for the system operating under block replacement
maintenance policy. The system response in terms of total cost, system downtime and
work in process inventory accumulation have been studied for continuous review inventory
policy. Various cost and system parameters have found to bear direct and significant effect
on the optimal values of the decision variables. The results obtained clearly show that the
joint optimized policy produces better results than that from the combinations of separately
or sequentially optimized policies.
