Unit 5 Flashcards
What is the primary objective of the maintenance department?
- ensure all productive resources perform at a high operating level, increase availability, increase performance, increase quality
- fixing & check ups
What are pros to maintence departments?
- reduced inventory
- lower operating costs
- faster, more dependable throughput
- improved capacity
- higher productivity
- improved quality
- continuous improvements
What are the 3 primary types of maintenance?
- corrective: all industrial equipment is exposed to wear or breakdowns
- preventative: the maintenance mission cannot only be repairing the breakdowns.
- autonomous
What are the types of corrective maintenance? and explain them?
urgent repairs- getting machines up a running after breakdowns, remainder of task schedule for later
scheduled corrective- result of urgent repairs, when rest of work is to be done.
What are types of preventative maintenance? explain.
- systematic preventative maintenance: goes by a replacement policy of the parts in the machines. eg. component needs to be replaced every 300 working hours.
- conditional/ predictive maintenance: goes by visual cues or defects in products. eg. temperature, noises, cracks, pressure losses
What is autonomous maintenance? explain.
- PM orders carried out by the production workers, maintenance orders
- they should be simple and graphically represented, many inspection tests should be carried out everyday
What is TPM?
Total Productive Maintenance
-proactive approach that aims to identify issues as soon as possible and plans to prevent issues before they happen
What are the objectives of TPM?
- zero defects
- zero work-related accidents
- zero breakdowns
What are the keys of TPM
- maximize the OEE, quality, performance and availability
- autonomous maintenance implementation
- preventative engineering
- training workers for maintenance improvements
- initial equipment management
What is RCM
Reliability-Centered Maintenance
What is the objective of RCM?
to determine the most effective maintenance tasks for critical components
What do you need prior to implementing RCM?
- complete maintenance and breakdown records for each piece of equipment
- a preventative maintenance program that runs properly
What are the tools to help RCM
- FMEA
- Reliability analysis
- statistical techniques
What is FMEA and how is it used in RCM?
Failure Mode and Effects Analysis
-method to analyze and discover all potential failure modes of a system (design, equipment processes), the effects of the failures, how to correct the effects on the system
How do you calculate RPN?
severity # x probability # x detections #
-the higher the RPN the greater the risk
What is a reliability analysis MTBF and how is it used in RCM?
it is the probability of how long the machine will work satisfactorily. The relative frequency of breakdowns.
eg. expect breakdowns every 10hrs
How do you calculate Reliability of MTBF?
Mean Time Between Failures
Operating time/ number of failures
What is maintainability MTTR?
-probability that the machine will take a certain amount of time to be repaired. eg. machine will be down for 4 hrs each breakdown
How do you calculate MTTR?
Mean Time To Recovery
Failures total time/ Number of failures
What is Statistical Availability?
the different times between breakdowns as well as each repair duration time are graphically represented in this process
How do you calculate Statistical availability?
MTBF / (MTBF + MTTR)
What is the reliability Bathtub Curve?
a graphic representation of the failure rate
- infant period, less failures
- useful period, observed normal failure rate
- waste period, increasing failure rate
