Standard Definitions and Measures for Failure Elimination Activities

Bảo trì có kế hoạch PM Planned Maintenance là một nội dung của bảo trì năng suất toàn diện TPM. Bảo trì có kế hoạch Planned Maintenance PM triển khai cho phòng bảo trì của công ty.

Standard failure definitions

Failure:

Condition that causes the equipment to completely lose its function (unplanned stoppages) and cause equipment down time.

Failures = Minor stops + Breakdowns + Process Failures

Minor Stop:

A “stop” is when a piece of equipment has a function loss or function reduction for ten minutes or less. “Stops” are normally recorded for AM performance assessment.

Breakdown:

A breakdown is when a piece of equipment has a function loss or function reduction greater than ten minutes and requires technician interface greater than “one touch” correction to restore its functions. Breakdowns” are normally recorded for PM performance assessment.

Examples: Corrosion, cracks, noise, vibration, heat, consumption due to friction, looseness, falling off bolts/ nuts or some parts/ assemblies, deformation, damage, overheat, generation of heat, contacting failure, short and short circuit, insulation failure, disconnection, sensor motion error, etc.

Process Failure:

Equipment process shutdown due to product out of control limits caused by changing properties of raw materials and subsidiary materials (ingredient variation from specifications - physical properties, chemistry), out of standard process conditions, disrupted services, miss operation, and other process disorders.

Examples: Out of quality, loosing production capacity, changing operation condition, blocking and clogging, dirt, corrosion and cracks (in a short period), etc.

Breakdown Classifications:

Classification	Papermaking, C&FP	Converting, Coremaking, Thermacare	Site Logistics	Utilities
Major	>6hrs	>2hrs	>2hrs	>6hrs
Intermediate	1 – 6 hrs	30 min. to 2 hrs	30 min. to 2 hrs	1 – 6 hrs
Minor	10 min to 60 min.	10 min. to 30 min.	10 min. to 30 min.	10 min to 60 min.

Failure positioning with respect to equipment losses

Standard Measure definitions:

Mean Time Between Failure = MTBF = (equipment operating time)/(# of failures)

Equipment operating time = Uptime

Mean Time to Repair = MTTR = (total breakdown time)/(# of BDs)

Mean Time Between Breakdown MTBBD = (equipment operating time)/(# of breakdowns)

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Ông: Nguyễn Đình Cương.

Chuyên viên Tư vấn Lean - TPM, công ty Tư vấn TST VN.