SKEDSOFT

Quality Control Engineering

Introduction to Condition Monitoring Techniques

Maintenance is the management, control, execution and quality of those activities which will ensure that optimum levels of availability and overall performance of plant are achieved, in order to meet business objectives - The British Department of Trade & Industry (DTI) (Rao, B.K.N.).

Maintenance strategies can be characterised as a) general purpose, b) essential and c) critical (Scheffer and Gridhar).

Maintenance Strategies (from Scheffer and Gridhar)

 

a) General Purpose

• Failure does not affect plant safety

• Not critical to plant production

• Machine has an installed spare or can operate on demand

• These machines require low to moderate expenditure, expertise and time to repair

• Secondary damage does not occur or is minimal

b) Essential Equipment

• Failure can affect plant safety

• Machine that are essential for plant operation and where shutdown will curtail a unit operation or part of the process

• They may or may not have an installed spare available

• Start-up is possible but may affect production process

• High power and speed might not be running continuously

• Some machines that demand time-based maintenance

• These machines require moderate expenditure, expertise and time to repair 

c) Critical Equipment

• If their failure can affect plant safety

• Machines that are essential for plant operation and where a shut-down will curtail the production process

• Machines which do not have spare parts

• These machines have high capital cost, they are very expensive to repair or take a long time to repair