In Total Productive Maintenance (TPM), everyone participates in maintenance. Both operators and maintenance experts have maintenance responsibilities. Operators clean their own machines and work areas (i.e. they have 'ownership') and undertake simple maintenance tasks. Maintenance staff have responsibility for operator training and for establishing maintenance procedures. Maintenance support involves concepts and actions that make preventative and productive maintenance possible.
TPM begins with an awareness of the six big losses:
- machine failure
- adjustments of machine
- minor stops in machine
- the operating speed of the machine
- defects produced by the machine
- yield of the machine
Each loss should be quantified and acted upon, in order of priority. Techniques to minimise maintenance times include: 'ready to go' trolleys' specifically for common failure types; light and sound systems for drawing attention and response clocks which measure all delays as they occur.
Optimal replacement and maintenance actions require good data. The JIT maintenance principle is to make data visible by having maintenance charts available on the machines and on walls near machines.
Maintenance should be measured, not by the traditional capacity measure of machine utilisation x efficiency, but by machine availability (i.e. availability when needed) x performance rate against required rate x quality performance (i.e. capability against target capability).
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Bicheno, J., Cause and Effect JIT: The Essentials of Lean Manufacturing, 2nd Edition, PICSIE Books, Buckingham, England, 1994 (ISBN 0 9513829 5 0)