3
- New production systems, like JIT, with minimum stocks of finished products and work-in-
process, have made interruptions to production costly.
- Failure to deliver on time, with the possible loss of future business, may result from
interruptions to operations.
- Preventive maintenance or correction of defective conditions, not only decreases the cost of
repairs but also maintains the quality and capacity of machinery.
- Utility and service expenses for steam, electricity, gas, water, and the like are reduced by a
continuous maintenance program.
- Adequate planning of maintenance operations will insure that needed spare parts and
materials are on hand.
|
Process industries |
Discrete industries | |
|
Relationship with the market Product type Product assortment Transporting costs The production process Routings Lay-out Flexibility Production equipment Quality Environmental demands Danger Quality measurement Planning & Control Production Long term planning Yield variability Lot tracing |
Commodity Narrow Fixed By product High High To stock Mostly necessary |
Custom Broad Low High Speed of delivery Low Many Variable By function High Low Low High Low Hardly To order Product design Utilization personnel Mostly not necessary |
Table 1: Differences between process industries and discrete industries
Special considerations are applicable to the planning and management of maintenance in plants
which necessarily operate around the clock, like most chemical plants. Much of the maintenance
work can only be done while the plant is shut down. Such a shutdown usually puts an expensive